Medical Reference Guide · Updated April 2026

The Complete
Peptide Guide
& Directory.

Every major therapeutic peptide explained — mechanisms of action, clinical applications, regulatory status, protocols, and how licensed providers use them. Written and reviewed by board-certified physicians.

ThriveAxis offers the best peptide therapy telehealth program available — 18 protocols, licensed provider oversight, quality-controlled compounding, and the only platform with a built-in peptide dosing calculator.

18
Peptides covered
6
Treatment categories
2
FDA-approved GLP-1 classes
MD
Reviewed by licensed physician
Medical Disclaimer: This guide is for educational purposes only and does not constitute medical advice. All peptide therapies require a prescription from a licensed medical provider following a proper evaluation. ThriveAxis patients access specific peptide protocols exclusively through their secure patient portal after a required provider consultation. Compounded peptide medications are not FDA-approved for human use unless otherwise noted.
Reviewed by Michael Harrington, MD — Medical Director, ThriveAxis Last updated April 4, 2026 NexResearch LLC DBA ThriveAxis
18 peptides
What You Need to Know First
Key Takeaway

Peptides are signaling molecules that decline with age. A properly designed, provider-supervised peptide protocol can significantly improve recovery, body composition, sleep quality, and biological markers of aging. ThriveAxis offers 18 distinct protocols — the most comprehensive formulary of any US telehealth platform.

Clinical Evidence Referenced in This Guide STEP-1 Trial (NEJM 2021): Semaglutide 2.4mg produced 14.9% mean body weight reduction vs 2.4% placebo over 68 weeks. SELECT Trial (NEJM 2023): Semaglutide reduced major cardiovascular events by 20% in patients with obesity and cardiovascular disease. Testosterone meta-analysis (JAMA 2020): TRT in men with hypogonadism produced significant improvements in lean body mass, sexual function, and mood. All protocols at ThriveAxis are reviewed by Michael Harrington MD against current published literature.

Peptides are the body's most precise signaling molecules.

What Are Peptides?

Peptides are short chains of amino acids — the same building blocks as proteins. Your body produces hundreds of them naturally. Therapeutic peptides are designed to mimic, amplify, or restore these natural signaling functions with extreme precision.

FDA Approved vs Compounded

Some peptides like semaglutide and tirzepatide have FDA-approved brand versions. Others are dispensed as compounded medications by state-licensed pharmacies. Regulatory status is noted clearly on every entry in this guide.

Prescription Required

Every peptide in this guide requires a prescription from a licensed medical provider. No reputable peptide therapy program should dispense medications without a proper evaluation. At ThriveAxis, all protocols are provider-determined.

Every peptide.
Fully explained.

GLP-1 & Metabolic Peptides
2 peptides · FDA-approved brand versions available
Semaglutide
Brand names: Wegovy®, Ozempic®, Rybelsus®
FDA ApprovedRx Only

The most-prescribed GLP-1 receptor agonist for chronic weight management. FDA-approved in injectable form (Wegovy) and pill form (Rybelsus). Ozempic is approved for type 2 diabetes and frequently prescribed off-label for weight loss.

Mechanism of Action

Semaglutide mimics the naturally occurring GLP-1 hormone released after eating. It slows gastric emptying, suppresses appetite signals in the brain, and stimulates insulin secretion while inhibiting glucagon. The net result is significantly reduced caloric intake and improved blood sugar regulation.

Clinical Uses
Chronic weight management Type 2 diabetes Cardiovascular risk reduction Metabolic syndrome
Protocol Notes

Typically started at 0.25mg weekly and titrated over 16-20 weeks to the target maintenance dose (0.5mg to 2.4mg weekly for weight loss). Subcutaneous injection once weekly. Your provider determines your titration schedule based on tolerance and response.

Key Research

STEP trials demonstrated 14.9% average body weight reduction over 68 weeks at the 2.4mg dose. SELECT trial showed 20% reduction in major cardiovascular events in patients with obesity and established cardiovascular disease.

Tirzepatide
Brand names: Zepbound®, Mounjaro®
FDA ApprovedRx Only

The first dual GLP-1 and GIP receptor agonist. Outperforms semaglutide in head-to-head weight loss studies. FDA-approved as Zepbound for obesity and Mounjaro for type 2 diabetes.

Mechanism of Action

Tirzepatide activates both GLP-1 and GIP receptors simultaneously — a dual-agonist mechanism no other approved drug achieves. GIP activation enhances the insulin sensitization effects and appears to reduce GI side effects compared to GLP-1 agonism alone. This dual action produces superior weight loss outcomes.

Clinical Uses
Chronic weight management Type 2 diabetes Insulin resistance NASH / fatty liver PCOS
Protocol Notes

Starting dose 2.5mg weekly, titrated every 4 weeks to a target of 5mg to 15mg weekly. Subcutaneous injection once weekly. The 2026 FDA enforcement environment has tightened compounding availability — your ThriveAxis provider will confirm current options.

Key Research

SURMOUNT-1 trial showed 20.9% average weight reduction at the 15mg dose over 72 weeks — the highest average weight loss ever recorded in a GLP-1 class trial. SURPASS trials demonstrated superior A1C reduction vs semaglutide in type 2 diabetes.

Growth Hormone Peptides
4 peptides · Compounded medications
Sermorelin
Growth Hormone Releasing Hormone (GHRH) Analog
CompoundedRx Only

The most widely used growth hormone secretagogue in clinical practice. Stimulates the pituitary gland to produce and release its own growth hormone naturally — safer than injecting HGH directly.

Mechanism of Action

Sermorelin is a synthetic analog of the first 29 amino acids of endogenous growth hormone releasing hormone. It binds to GHRH receptors in the pituitary gland, stimulating the natural pulsatile release of growth hormone. Unlike direct HGH injection, sermorelin works with the body's natural feedback loop — preventing suppression of endogenous GH production.

Clinical Uses
GH deficiency Anti-aging / longevity Body composition Sleep quality Recovery Libido
Protocol Notes

Typically administered subcutaneously before sleep at doses of 100-300mcg per night, 5 days per week. Often combined with Ipamorelin for synergistic effect. Cycles of 3-6 months are common. Compounded with bacteriostatic water — your ThriveAxis dosing calculator handles all mixing math.

CJC-1295
Modified GHRH Analog — DAC and non-DAC forms
CompoundedRx Only

A modified GHRH analog with a dramatically longer half-life than sermorelin. The DAC (Drug Affinity Complex) version binds to albumin, extending activity to 6-8 days per injection.

Mechanism of Action

CJC-1295 modifies the GHRH sequence with substitutions at positions 2, 8, 15, and 27 that prevent enzymatic degradation. The DAC form adds a lysine-maleimide group that binds covalently to albumin in the bloodstream, creating a sustained-release depot. The result is a dramatically longer half-life — hours vs days — vs native GHRH.

Clinical Uses
Elevated IGF-1 levels Muscle gain Fat loss Anti-aging Recovery acceleration
Protocol Notes

Non-DAC form: 100mcg subcutaneously once daily. DAC form: 2mg subcutaneously 1-2 times per week. Almost always combined with Ipamorelin in clinical practice to maximize the GH pulse. Your provider determines which form is appropriate for your protocol.

Ipamorelin
Growth Hormone Releasing Peptide (GHRP)
CompoundedRx Only

The most selective and well-tolerated GHRP available. Stimulates GH release without significantly affecting cortisol or prolactin — the cleanest growth hormone secretagogue in clinical use.

Mechanism of Action

Ipamorelin is a pentapeptide GHRP that binds to ghrelin receptors (GHS-R1a) in the pituitary and hypothalamus. Unlike GHRP-2 and GHRP-6, Ipamorelin does not significantly raise cortisol or prolactin, making it exceptionally clean. It produces a strong, selective GH pulse within 30-45 minutes of administration. Combined with CJC-1295 or Sermorelin, it creates synergistic amplification of GH release.

Clinical Uses
GH pulse optimization Body composition Sleep improvement Recovery Skin quality
Protocol Notes

100-300mcg subcutaneously before sleep. Most effective when combined with CJC-1295 (non-DAC) in the same injection. The combination creates the "CJC/Ipamorelin stack" — the most commonly prescribed peptide combination in anti-aging and performance medicine. Your ThriveAxis dosing calculator shows exact reconstitution math.

Tesamorelin
Brand name: Egrifta® — Synthetic GHRH Analog
FDA ApprovedRx Only

The only FDA-approved GHRH analog. Approved specifically for HIV-related lipodystrophy but used off-label for visceral fat reduction and body composition in broader populations.

Mechanism of Action

Tesamorelin is a synthetic form of GHRH with a trans-3-hexenoic acid group attached to the N-terminus, increasing stability. It stimulates pulsatile GH release from the pituitary with high potency and selectivity. Its primary documented effect is significant reduction in visceral adipose tissue — the dangerous fat surrounding internal organs.

Clinical Uses
HIV-associated lipodystrophy (FDA approved) Visceral fat reduction Non-alcoholic fatty liver (NAFLD) Cognitive function
Protocol Notes

FDA-approved dose: 2mg subcutaneously once daily. Effects on visceral fat are typically seen within 26 weeks. As an FDA-approved agent, Egrifta has the strongest regulatory standing of all GHRH analogs. Off-label use requires provider clinical judgment and is only available after evaluation.

Recovery & Tissue Repair Peptides
3 peptides · Compounded medications
BPC-157
Body Protection Compound — 15 amino acid sequence
CompoundedRx Only

Derived from a protein found in gastric juice. Demonstrated remarkable tissue healing properties in preclinical studies — tendons, ligaments, muscle, gut, and nerve tissue. Widely used in sports medicine and recovery protocols.

Mechanism of Action

BPC-157 upregulates growth factor receptors (including VEGFR2), promotes angiogenesis (new blood vessel formation), and modulates the nitric oxide system. It appears to accelerate the formation of granulation tissue and tendon-to-bone healing. It also demonstrates gut-protective effects by stabilizing the gastric mucosa and accelerating healing of intestinal damage. Acts on multiple pathways simultaneously — anti-inflammatory, angiogenic, and neuroprotective.

Clinical Uses
Tendon & ligament repair Muscle recovery Gut healing (IBD, leaky gut) NSAID damage reversal Nerve repair Joint injury
Protocol Notes

Typically 250-500mcg subcutaneously once or twice daily, or orally for gut-specific applications (250mcg-1mg in capsule form). Cycles of 4-12 weeks depending on the indication. Note: BPC-157 does not have human clinical trial data — existing evidence is from animal models. Your provider will discuss the evidence base and determine if it is appropriate for you.

TB-500
Thymosin Beta-4 Synthetic Analog
CompoundedRx Only

A synthetic version of the naturally occurring Thymosin Beta-4 peptide found in virtually every cell. Promotes wound healing, reduces inflammation, and enhances tissue repair — particularly in cardiac and musculoskeletal tissue.

Mechanism of Action

Thymosin Beta-4 sequesters actin monomers and promotes actin polymerization, which is essential for cell migration and tissue repair. It upregulates genes involved in angiogenesis, reduces inflammatory cytokines including TNF-alpha and IL-6, and stimulates progenitor cell differentiation. Often described as a master regulator of cell and organ protection and regeneration.

Clinical Uses
Chronic injury recovery Inflammation reduction Cardiac tissue protection Wound healing Hair growth
Protocol Notes

Loading phase: 4-8mg per week for 4-6 weeks (split into 2 injections). Maintenance: 2-6mg per week. Often stacked with BPC-157 for injury recovery — the combination is frequently called the "healing stack." Most useful for chronic or stubborn injuries not responding to conventional treatment.

GHK-Cu
Copper Tripeptide — Glycyl-L-Histidyl-L-Lysine Copper Complex
CompoundedRx Only

A naturally occurring copper complex found in human plasma, saliva, and urine. Concentrations decline sharply with age. Stimulates collagen and elastin synthesis, accelerates wound healing, and has potent antioxidant properties.

Mechanism of Action

GHK-Cu activates over 4,000 genes involved in wound healing, skin remodeling, and antioxidant defense. It stimulates collagen types I, II, III, IV, VII, and XVII, as well as elastin and fibronectin. It resets gene expression to a younger state and has demonstrated anti-metastatic properties in early research. The copper complex acts as a potent antioxidant and superoxide dismutase inducer.

Clinical Uses
Skin rejuvenation Collagen stimulation Wound healing Hair growth restoration Anti-aging
Protocol Notes

Topical: 1-2% concentration applied daily. Subcutaneous: 1-2mg 2-3x weekly. Topical application is the most common route for skin benefits. Systemic administration for broader anti-aging effects requires provider determination. Notable for having both topical cosmetic and systemic therapeutic applications.

Hormonal & Reproductive Peptides
3 peptides
PT-141
Bremelanotide · Brand name: Vyleesi® (FDA approved for women)
FDA Approved (Women)Rx Only

The only peptide that addresses sexual dysfunction through the central nervous system rather than the vascular system. FDA-approved as Vyleesi for premenopausal women with HSDD. Also used off-label for male erectile dysfunction.

Mechanism of Action

PT-141 activates melanocortin receptors (MC3R and MC4R) in the central nervous system — the hypothalamus specifically. Unlike PDE5 inhibitors (Viagra, Cialis) which work peripherally on blood vessels, PT-141 works centrally to activate sexual arousal pathways in the brain. This makes it effective for psychogenic sexual dysfunction and for patients who don't respond to peripheral approaches.

Clinical Uses
HSDD in women (FDA approved) Erectile dysfunction (off-label) Low libido (men and women) Psychogenic sexual dysfunction
Protocol Notes

Women (Vyleesi): 1.75mg subcutaneous injection 45 minutes before sexual activity. Men (off-label): 1-2mg subcutaneous injection 1-2 hours before activity. Not for daily use. Notable side effect: transient facial flushing and nausea — usually mild. Contraindicated with certain cardiovascular medications. Provider evaluation required.

Kisspeptin
KiSS-1 Derived Peptide — Metastin
CompoundedRx Only

The master regulator of the reproductive axis. Kisspeptin neurons in the hypothalamus control GnRH pulsatility — the root driver of LH, FSH, testosterone, and estrogen production. Emerging as a powerful tool in hormone optimization.

Mechanism of Action

Kisspeptin binds to GPR54 receptors on GnRH neurons, stimulating pulsatile GnRH release. GnRH then drives LH and FSH secretion from the pituitary, which in turn stimulates testosterone production in men and estrogen/progesterone in women. It effectively resets the reproductive hormone axis from the top down — useful for patients with hypogonadotropic hypogonadism and those coming off TRT who want to restore natural production.

Clinical Uses
Post-TRT natural recovery Hypogonadotropic hypogonadism Fertility support LH/FSH optimization
Protocol Notes

Investigational in most clinical settings — use is highly protocol-specific and requires comprehensive hormone panel evaluation. Doses vary widely by indication. Most commonly used in post-TRT recovery protocols alongside Clomiphene or HCG. Your provider determines if Kisspeptin is appropriate for your specific hormonal situation.

Oxytocin
Neuropeptide Hormone — Pitocin® (IV form FDA approved)
CompoundedRx Only

The "bonding hormone" — naturally produced in the hypothalamus and released by the pituitary. Beyond social bonding, oxytocin plays critical roles in stress regulation, pain modulation, gut function, and metabolic health.

Mechanism of Action

Oxytocin binds to G protein-coupled oxytocin receptors distributed throughout the brain and body. In the central nervous system it reduces amygdala reactivity (fear and stress response) and increases social approach behavior. Peripherally it modulates pain signaling, gut motility, and has anti-inflammatory effects via suppression of NF-kB pathways. It also appears to reduce food intake and improve insulin sensitivity.

Clinical Uses
Stress and anxiety reduction Social anxiety Appetite regulation Pain management Gut motility PTSD (off-label)
Protocol Notes

Intranasal: 10-40 IU per nostril as needed. Sublingual troches: 25-100 IU. Routes vary by indication. Compounded intranasal oxytocin is the most practical delivery method for outpatient use. Pitocin (IV oxytocin) is FDA-approved for labor induction only. All compounded forms require provider prescription and evaluation.

Cognitive & Neuroprotective Peptides
2 peptides · Research-grade
Selank
Synthetic Peptide — Tuftsin Analog (TP-7)
CompoundedRx Only

A synthetic heptapeptide derived from the immunomodulatory peptide Tuftsin. Approved in Russia for anxiety treatment. Demonstrates anxiolytic effects comparable to benzodiazepines without sedation, dependence, or cognitive impairment.

Mechanism of Action

Selank modulates GABA-A receptors (similar to benzodiazepines but without the addiction liability), increases BDNF expression in the hippocampus, and regulates enkephalin metabolism — the body's natural opioid-like molecules involved in anxiety and mood. It also modulates IL-6 and other inflammatory cytokines, suggesting an immune-regulatory component to its anxiolytic effects.

Clinical Uses
Generalized anxiety Cognitive enhancement Memory improvement ADHD (off-label) Depression support
Protocol Notes

Intranasal: 250-1000mcg per nostril, 1-3 times daily. Subcutaneous: 250-3000mcg per injection. Intranasal is most convenient for daily use. Cycles of 10-14 days are common, with 5-7 day breaks. Non-habit forming — no withdrawal syndrome documented. Well-tolerated in published research. Provider evaluation required for US access.

Semax
ACTH(4-7)-Pro-Gly-Pro Neuropeptide Analog
CompoundedRx Only

A fragment of ACTH (adrenocorticotropic hormone) modified for stability and CNS penetration. Used clinically in Russia for stroke recovery, ADHD, and cognitive enhancement. One of the most studied nootropic peptides.

Mechanism of Action

Semax dramatically increases BDNF (Brain-Derived Neurotrophic Factor) and NGF (Nerve Growth Factor) in the hippocampus and prefrontal cortex. It enhances dopaminergic and serotonergic neurotransmission, modulates melanocortin receptors involved in attention and learning, and demonstrates neuroprotective effects in ischemic brain injury models. It crosses the blood-brain barrier efficiently via intranasal administration.

Clinical Uses
Cognitive enhancement ADHD support Stroke recovery Depression Memory and focus Neuroprotection
Protocol Notes

Intranasal drops: 200-900mcg daily (1-3 drops per nostril of 1% solution). Effects on focus and mental clarity often noticed within hours. Neuroprotective benefits accumulate over weeks. Frequently combined with Selank for a "cognitive stack." Cycles of 10-14 days are typical. Provider evaluation required for US access as a compounded medication.

Longevity & Anti-Aging Peptides
2 peptides
Epithalon
Tetrapeptide — Ala-Glu-Asp-Gly (AEDG)
CompoundedRx Only

A synthetic tetrapeptide derived from the pineal gland peptide Epithalamin. Clinically shown to extend telomere length, regulate circadian rhythm, and demonstrate significant anti-aging effects in multiple long-term studies — including a 12-year lifespan extension study in humans.

Mechanism of Action

Epithalon activates telomerase enzyme production, which rebuilds and extends telomeres — the protective caps on chromosomes that shorten with each cell division. It also regulates melatonin production via the pineal gland, restoring circadian rhythm. It reduces oxidative stress, normalizes antioxidant defense (superoxide dismutase, catalase, glutathione peroxidase), and has demonstrated oncostatic (anti-cancer) properties in animal studies.

Clinical Uses
Telomere lengthening Sleep restoration Anti-aging Oxidative stress reduction Immune regulation
Protocol Notes

5-10mg subcutaneously or IV, once daily for 10-20 consecutive days. Protocol typically run 1-2 times per year. Some practitioners use smaller daily subcutaneous doses over longer periods. Backed by a unique human clinical dataset — Russian researchers conducted 12+ year follow-up studies showing 1.6-1.8x reduction in mortality risk in treated groups vs controls.

MOTS-c
Mitochondrial Open Reading Frame — 16S rRNA-encoded Peptide
CompoundedRx Only

One of the most novel discoveries in peptide science — a mitochondria-encoded peptide that regulates metabolism, promotes exercise-like effects, and extends lifespan in animal models. Circulating levels decline significantly with age.

Mechanism of Action

MOTS-c is encoded in the mitochondrial genome — unusual for a bioactive peptide. It activates AMPK (the master metabolic regulator), promotes glucose uptake and fatty acid oxidation, and reduces insulin resistance. Under metabolic stress, it translocates to the nucleus and regulates adaptive nuclear gene expression. In aging models, it restores the adaptive response to exercise stress that declines with age, effectively producing exercise-mimetic effects.

Clinical Uses
Insulin sensitivity Exercise capacity Metabolic syndrome Obesity Longevity Mitochondrial function
Protocol Notes

5-10mg subcutaneously 2-5 times weekly. Often administered before exercise to amplify training response. Relatively newer to clinical practice — evidence base is growing rapidly. Most compelling for patients with metabolic syndrome or significant insulin resistance who want to amplify lifestyle interventions. Provider evaluation and monitoring are essential.

Peptides by your goal.

Every protocol is built around your specific goals, bloodwork, and health history. These are common clinical combinations — your provider determines what is right for you.

Weight Loss & Metabolism
The most impactful combination starts with a GLP-1 agonist for appetite and insulin regulation, layered with metabolic peptides for fat oxidation and energy.
Semaglutide Tirzepatide MOTS-c AOD-9604
Muscle & Performance
Growth hormone secretagogues amplify natural GH pulsatility, driving muscle protein synthesis, fat metabolism, and recovery — without suppressing endogenous production.
CJC-1295 Ipamorelin Sermorelin TB-500
Injury & Recovery
The healing stack targets tissue repair at multiple levels — blood vessel formation, collagen synthesis, inflammation reduction, and cellular migration.
BPC-157 TB-500 GHK-Cu Ipamorelin
Longevity & Anti-Aging
Targeting the biological mechanisms of aging — telomere maintenance, mitochondrial function, oxidative stress, and circadian rhythm restoration.
Epithalon GHK-Cu MOTS-c Sermorelin
Cognitive & Mental Clarity
BDNF-boosting peptides improve neuroplasticity, reduce anxiety, and enhance focus without the side effects or dependency of pharmaceutical nootropics.
Semax Selank Oxytocin BPC-157
Sexual Health & Hormones
Addressing libido, erectile function, and hormonal optimization through both central (brain) and peripheral mechanisms — often layered with TRT or BHRT.
PT-141 Kisspeptin Oxytocin Sermorelin
Common Questions

Peptide FAQ

FDA-approved peptides like Wegovy (semaglutide) and Zepbound (tirzepatide) have undergone rigorous clinical trials demonstrating safety and efficacy for specific indications. Compounded peptides like BPC-157, Sermorelin, and CJC-1295 are prepared by state-licensed compounding pharmacies but have not been evaluated by the FDA for safety, efficacy, or quality for the intended use. This does not mean they are unsafe — it means the regulatory pathway is different. Your ThriveAxis provider will clearly explain the status of each medication in your protocol.
Many peptides are available in non-injectable forms depending on the molecule and indication. BPC-157 can be taken as an oral capsule for gut-specific applications. Selank and Semax are administered as intranasal drops. Oxytocin is available as a nasal spray or sublingual troche. However, most systemic peptide therapy is most effective when administered subcutaneously — small insulin-style injections using tiny needles that most patients find straightforward. Your ThriveAxis dosing calculator walks you through mixing and administration step by step.
Timeline varies significantly by peptide and indication. GLP-1 agonists (semaglutide, tirzepatide) typically produce noticeable appetite reduction within 1-2 weeks, with significant weight loss results by week 8-12. Growth hormone peptides (Sermorelin, CJC/Ipamorelin) take longer — improved sleep quality often noticed within 2-4 weeks, body composition changes in 3-6 months. BPC-157 injury recovery can begin within 2-4 weeks for acute injuries. Cognitive peptides (Semax, Selank) often produce noticeable effects within days to weeks. Your provider will set realistic expectations for your specific protocol.
Your ThriveAxis provider determines your protocol after a required medical evaluation that includes your health history, goals, symptoms, and bloodwork results. There is no self-prescribing at ThriveAxis — and there should not be anywhere. Peptide selection depends on your individual physiology, existing conditions, medications, and goals. What works for one person may be contraindicated for another. This is exactly why the provider consultation is required before any medication is prescribed.
FDA-approved peptides (semaglutide, tirzepatide) have well-characterized safety profiles from large clinical trials. Common GLP-1 side effects include nausea, constipation, and injection site reactions — typically mild and dose-dependent. Compounded peptides like BPC-157 and TB-500 have not been studied in large-scale human trials, but have favorable safety profiles in smaller studies and clinical practice. Growth hormone secretagogues can cause water retention, joint aches, and carpal tunnel at higher doses. No peptide should be used without provider supervision, regular monitoring, and honest reporting of side effects.
ThriveAxis membership starts at $149 per month (Foundation) or $249 per month (Optimizer — includes peptide therapy access). Medication costs are separate and depend on your provider-determined protocol. GLP-1 medications vary by dose and formulation. Compounded peptide protocols like CJC/Ipamorelin or BPC-157 typically run $150-400 per month depending on dose and frequency. Your provider will give you a clear cost breakdown for your specific protocol before you commit to anything.

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Special Report · Updated April 2026

The next generation
of GLP compounds — explained.

Retatrutide. GLP-2. "GLP-3." "GLP-4." These terms are everywhere — in clinics, on social media, in patient questions. Most of what circulates is either partially accurate, completely wrong, or being called something it is not. Here is the straight story, sourced from clinical trial data and FDA records, as of April 2026.

Educational content only. None of the investigational compounds described in this section are available through ThriveAxis or prescribable by any US provider outside of clinical trials. This section exists to answer the questions patients are already asking — with accurate information, not speculation. ThriveAxis will update this section as FDA approvals occur.
The GLP Evolution — Generation by Generation
FDA Approved
First Generation
Single Agonist
Wegovy®, Ozempic®, Rybelsus®
~15%avg body weight loss — STEP-1
GLP-1
FDA Approved
Second Generation
Dual Agonist
Zepbound®, Mounjaro®
~21%avg body weight loss — SURMOUNT-1
GLP-1 GIP
Phase 3 — Not Approved
Third Generation
Triple Agonist
Retatrutide (LY3437943) — Eli Lilly
~29%avg body weight loss — TRIUMPH-4, 68 wks
GLP-1 GIP Glucagon
Oral — FDA Approved Apr 2026
Oral Revolution
Small Molecule GLP-1
Foundayo® (orforglipron) — Eli Lilly
~12%avg body weight loss — Phase 3, 72 wks
GLP-1 No injection

Retatrutide — the triple agonist.

LY3437943 · Eli Lilly · GIP + GLP-1 + Glucagon receptor agonist

Not FDA Approved Phase 3 — 8 Trials Active
28.7%
avg body weight loss at 12mg — TRIUMPH-4, 68 weeks
71.2 lbs
average pounds lost — TRIUMPH-4 top dose
3
hormone receptors activated — GLP-1, GIP, and glucagon
2027–28
projected FDA approval — pending full TRIUMPH program readouts

How It Works

Retatrutide is a triple hormone receptor agonist — a single weekly injection that simultaneously activates three separate receptors: GLP-1, GIP, and glucagon. Tirzepatide (Zepbound) activates two. Semaglutide activates one. Each additional receptor adds another mechanism of metabolic action.

The glucagon receptor is what makes retatrutide different. Glucagon is a catabolic hormone that raises blood sugar and increases energy expenditure — normally, it is the counter to insulin. By co-activating the glucagon receptor at controlled doses alongside GLP-1 and GIP, retatrutide boosts resting energy expenditure (calorie burn at rest), which neither semaglutide nor tirzepatide does. This is why the weight loss numbers are higher.

TRIUMPH-4 results (December 2025): In adults with obesity and knee osteoarthritis, the 12mg dose produced 28.7% average body weight loss at 68 weeks — beating tirzepatide's 20.9% and semaglutide's 14.9% in their respective landmark trials. Pain scores dropped 75.8%. Cardiovascular risk markers including cholesterol, triglycerides, and blood pressure all improved significantly.

TRANSCEND-T2D-1 (March 2026): In adults with type 2 diabetes, 17% weight loss at 40 weeks with no plateau observed — patients were still losing at trial end. A1C dropped by up to 2 full percentage points.

Seven additional Phase 3 trials are running in 2026 covering obesity, sleep apnea, liver disease, and cardiovascular outcomes. TRIUMPH-1 — with an 80-week duration — could show over 30% weight loss, according to analyst projections.

Comparing to What's Available Now

Head to head against current FDA-approved options, retatrutide produces meaningfully greater weight loss. The question is not whether it is more effective — the clinical data is clear. The question is tolerability, safety, and whether the additional weight loss justifies the additional risk profile of a new mechanism.

Safety & Tolerability — The Honest Picture

Phase 3 data revealed more tolerability challenges than Phase 2 suggested. This is normal as larger, more diverse patient populations are studied.

  • Discontinuation rate: 18.2% of patients on 12mg stopped due to adverse events — versus 4% on placebo. This is significantly higher than tirzepatide or semaglutide discontinuation rates.
  • GI side effects: Nausea, vomiting, and diarrhea — consistent with all GLP-1 class medications. Generally mild to moderate.

New safety signal — Dysesthesia: Up to 20.9% of patients on the 12mg dose experienced dysesthesia — an abnormal skin sensation where normal touch feels unusual, uncomfortable, or painful. This was not observed in Phase 2. Lilly reports it was mild in most patients and rarely caused discontinuation, but analysts flagged it as a signal to watch across remaining TRIUMPH trials. It does not appear to be related to a known systemic disease in this context — but the mechanism is not yet fully understood.

  • BMI correlation: Patients with BMI 35 or higher had significantly lower discontinuation rates (8.8-12.1%) than lower-BMI patients. The drug appears better tolerated in patients with higher baseline obesity.
  • Osteoarthritis benefit: The dual endpoint of weight loss plus 75.8% pain reduction in a knee OA population is clinically significant — suggesting retatrutide may eventually receive label indications beyond obesity alone.

Timeline & Availability

  • Phase 3 readouts: Seven more TRIUMPH trials expected to report throughout 2026
  • NDA filing: Likely late 2026 or early 2027 once TRIUMPH program is complete
  • FDA approval projection: Analysts and GlobalData project 2027-2028
  • Revenue projection: $30 billion by 2031 (GlobalData) — making it potentially the highest-selling drug in history
  • Available now: No. Not through ThriveAxis. Not through any US provider. Clinical trial enrollment only.
Head to Head — All Generations
Compound Mechanism Status Avg Weight Loss Dosing Key Advantage
Semaglutide (Wegovy) GLP-1 single agonist FDA Approved 2021 ~15% Weekly injection Longest safety record. SELECT CV data.
Tirzepatide (Zepbound) GLP-1 + GIP dual agonist FDA Approved 2023 ~21% Weekly injection Best approved weight loss. Fewer GI effects.
Oral semaglutide (Wegovy pill) GLP-1 single agonist — oral FDA Approved Dec 2025 ~14% Daily pill — food restrictions First oral GLP-1 for weight loss.
Orforglipron (Foundayo) Small-molecule GLP-1 — oral FDA Approved Apr 1, 2026 ~12% Daily pill — no restrictions No food/water rules. No refrigeration. $25/mo with insurance.
CagriSema GLP-1 + Amylin (cagrilintide) Phase 3 — filing 2025 ~25% Weekly injection Amylin pathway — different mechanism than GIP. Approval 2027.
Retatrutide GLP-1 + GIP + Glucagon triple agonist Phase 3 — 8 trials active ~29% Weekly injection Highest weight loss ever recorded in a Phase 3 obesity trial. Boosts resting energy expenditure. Also benefits OA pain, sleep apnea, cardiovascular.
MariTide (Maridebart) GLP-1 + GIPR antagonist Phase 3 — Amgen TBD Monthly injection Monthly dosing. Phase 3 results expected 2027.
Other Pipeline Compounds Worth Knowing
CagriSema
Cagrilintide + Semaglutide — Novo Nordisk
Phase 3 — FDA Filing 2025
MechanismGLP-1 + Amylin analog
Weight lossUp to ~25%
Unique angleAmylin targets different brain circuits than GLP-1 — additive effect
Expected approval2027 (H2 2026 FDA decision)
Projected salesMajor — Novo's answer to retatrutide
MariTide
Maridebart Cafraglutide — Amgen
Phase 3 — Results 2027
MechanismGLP-1 agonist + GIPR antagonist
Key differentiatorMonthly injection — not weekly
Muscle preservationEarly data shows potential advantage
Phase 3 resultsExpected 2027
Approval estimate2028 at earliest
Amycretin
Amylin + GLP-1 combo — Novo Nordisk
Phase 2 Complete
MechanismAmylin + GLP-1 combined molecule
Phase 2 weight lossUp to ~22% at 36 weeks
Advantage over CagriSemaSingle molecule — simpler manufacturing
StatusPhase 3 planning stage
Availability2028-2029 at earliest

GLP-1, GLP-2, "GLP-3," and "GLP-4" —
what's real and what's not.

Real — FDA Approved for Weight Loss GLP-1 (Glucagon-Like Peptide-1)
This is the real one. GLP-1 is a naturally occurring gut hormone that signals satiety, slows gastric emptying, and triggers glucose-dependent insulin release. GLP-1 receptor agonists — semaglutide, tirzepatide, orforglipron — activate this receptor with much greater potency and duration than the natural hormone. This is the foundational mechanism behind every approved weight loss medication on the market today. When people say "GLP-1 drugs," this is what they mean.
Real Hormone — NOT a Weight Loss Drug GLP-2 (Glucagon-Like Peptide-2)
GLP-2 is a real hormone — but it does the opposite of what weight loss patients want. GLP-2 is produced in the intestine and its primary job is to promote intestinal growth and improve nutrient absorption. It stimulates the gut lining to grow, increases blood flow to the intestines, and enhances the absorption of nutrients through the gut wall. The only FDA-approved GLP-2 receptor agonist is Teduglutide (Gattex) — a treatment for Short Bowel Syndrome in patients whose intestines cannot absorb enough nutrients. It has nothing to do with weight loss. When patients ask about "GLP-2 for weight loss" they are most likely confusing it with one of the dual or triple agonist compounds — or have seen the term used incorrectly on social media. There is no approved GLP-2 weight loss medication and none in late-stage trials for obesity.
Not a Scientific Term — Media Slang "GLP-3" — What People Are Actually Talking About
"GLP-3" is not a medical or scientific term. It does not refer to a hormone, a receptor, or a drug class recognized by the FDA, endocrinology societies, or pharmacology literature. This phrase emerged in mainstream media and on social media as informal shorthand for retatrutide's triple-agonist mechanism — the logic being "GLP-1 is one receptor, GLP-1+GIP is two, so the triple agonist must be GLP-3." That is not how pharmacology naming works. The correct term for retatrutide's mechanism class is "triple hormone receptor agonist" or "GIP/GLP-1/glucagon triple agonist." When you hear "GLP-3," the person is almost certainly talking about retatrutide. Now you know more than they do.
Does Not Exist — Social Media Confusion "GLP-4" — What Is This, Really?
"GLP-4" is not a real term in any medical, pharmacological, or clinical context. There is no GLP-4 hormone, no GLP-4 receptor, and no drug being developed that calls itself a "GLP-4 agonist." When patients or influencers use this term, they are typically doing one of three things:
  • Extending the informal GLP-1/GLP-2/GLP-3 numbering logic one step further to describe compounds beyond triple agonists — including CagriSema, Amycretin, or quad-agonist concepts still in early research
  • Confusing the escalating generation numbers (first-gen, second-gen, third-gen) with a hormone numbering system
  • Repeating terminology from social media content that was itself inaccurate
If someone tells you they are taking "GLP-4" or asks about getting a "GLP-4" prescription — they are using a term that has no clinical meaning. Ask them specifically what drug they are referring to. The answer will typically be retatrutide, CagriSema, or a next-generation compound they read about online. None of these are available through any US prescriber outside of clinical trials as of April 2026.
FDA Approved April 1, 2026 Orforglipron (Foundayo) — The Oral Revolution
Worth naming here because it is generating as much patient discussion as retatrutide and is frequently confused with it. Orforglipron (brand name Foundayo) received FDA approval on April 1, 2026 — making it the first small-molecule, non-peptide oral GLP-1 receptor agonist approved for weight loss. Unlike oral semaglutide (the Wegovy pill), orforglipron has no food or water restrictions and requires no refrigeration. Phase 3 data showed approximately 12.4% weight loss at 72 weeks in adults with obesity. Available through Eli Lilly's LillyDirect platform at $25/month with commercial insurance or $149/month self-pay. This is a real drug that is available now. It is not as potent as the injectable GLP-1s for weight loss — but for patients who cannot or will not self-inject, it is a meaningful clinical option. Discuss with your ThriveAxis provider whether it is appropriate for your protocol.
The Bottom Line on Next-Gen GLP

The GLP landscape is moving faster than at any point in the history of obesity medicine. Retatrutide will likely become the highest-efficacy weight loss drug ever approved — if its safety profile holds up across the remaining TRIUMPH trials. CagriSema and Amycretin represent different mechanistic bets from Novo Nordisk. Orforglipron already exists and is already available. The "GLP-3" and "GLP-4" terms you see circulating are not scientific — but they point toward real clinical momentum that is genuinely exciting for patients who have not responded to existing options.

What ThriveAxis Will Do

ThriveAxis will update this section as new trial data is released and as FDA approvals occur. When retatrutide is approved — projected 2027-2028 — ThriveAxis will evaluate it for inclusion in patient protocols based on clinical evidence, prescriber training, and pharmacy availability.

If you have questions about any of these compounds, bring them to your provider visit. The conversation is completely appropriate — your provider should be current on the landscape. That is part of what ThriveAxis is built for.

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Real result. Documented. Not a stock photo.
202 lbs 217 lbs lean.
Kyle Holland, ThriveAxis Co-Founder.
Gained 15 lbs of lean muscle. Dropped body fat. TRT + peptide protocol. Documented with photos throughout.
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