Peptides: The Complete Guide
Peptides are short chains of amino acids — typically 2 to 50 — that act as signaling molecules in the body. Some are FDA-approved medications; many others remain investigational. They are used across medicine, performance optimization, and longevity research, with applications ranging from tissue repair and growth hormone modulation to immune support and neuroprotection.
Navigate by Therapeutic Goal
Each category groups peptides by their primary clinical application. Select a category to jump to its comparison table, or scroll for a complete overview.
Regulatory Update — March 2026
On February 27, 2026, HHS Secretary Robert F. Kennedy Jr. announced that approximately 14 of 19 peptides previously placed on the FDA's Category 2 restricted list will be moved back to Category 1 — restoring legal access through licensed compounding pharmacies with a physician's prescription. The formal updated list has not yet been published. Reclassification to Category 1 does not constitute FDA approval. The regulatory status information below reflects the most current publicly available data as of March 2026.
Recovery & Healing
Peptides studied for tissue repair, anti-inflammatory activity, and accelerated wound healing.
| Peptide | Expected Results | Evidence | Status | Side Effects | Cost/Mo |
|---|---|---|---|---|---|
| BPC-157 Gastric pentadecapeptide for tissue repair |
|
✓✓ Limited human — extensive animal data, limited human trials | Returning to Cat. 1; WADA-banned |
|
$150–$495 |
| TB-500 Thymosin Beta-4 fragment for repair |
|
✓ Mostly preclinical — animal + anecdotal | Returning to Cat. 1; WADA-banned |
|
$150–$450 |
| KPV Alpha-MSH anti-inflammatory tripeptide |
|
✓ Mostly preclinical — in vitro + animal | Returning to Cat. 1 |
|
$100–$300 |
| GHK-Cu Copper peptide for wound healing |
|
✓✓ Limited human — small skin studies + animal | Returning to Cat. 1; OTC topical available |
|
$50–$300 |
GH & Performance
Peptides that stimulate endogenous growth hormone production. Several are FDA-approved or have extensive Phase 2/3 trial data.
| Peptide | Expected Results | Evidence | Status | Side Effects | Cost/Mo |
|---|---|---|---|---|---|
| CJC-1295 GHRH analog, often paired with Ipamorelin |
|
✓✓ Limited human — some clinical pharmacokinetic data | Returning to Cat. 1 |
|
$150–$400 |
| Ipamorelin Selective ghrelin receptor agonist |
|
✓✓ Limited human — post-surgical trials | Returning to Cat. 1 |
|
$150–$400 |
| Sermorelin GHRH analog (first 29 amino acids) |
|
✓✓✓ Early clinical — FDA-approved diagnostic, off-label GH | FDA-approved (Geref, discontinued brand; compounding available) |
|
$99–$400 |
| Tesamorelin GHRH analog for visceral fat reduction |
|
✓✓✓✓ Strong clinical — FDA-approved for lipodystrophy | FDA-approved (Egrifta SV, 2010) |
|
$500–$1,000+ |
| MK-677 Oral ghrelin mimetic (Ibutamoren) |
|
✓✓✓ Early clinical — multiple human trials, not approved | Research chemical; WADA-banned |
|
$50–$150 |
| GHRP-2 GH-releasing peptide, ghrelin receptor |
|
✓✓ Limited human — diagnostic use studies | Research chemical; WADA-banned |
|
$100–$250 |
| GHRP-6 GH-releasing peptide, strong appetite effect |
|
✓✓ Limited human — similar to GHRP-2 | Research chemical; WADA-banned |
|
$100–$250 |
Weight Management
Peptides and small molecules investigated for fat metabolism, energy expenditure, and body composition.
| Peptide | Expected Results | Evidence | Status | Side Effects | Cost/Mo |
|---|---|---|---|---|---|
| AOD-9604 Modified hGH fragment for fat loss |
|
✓✓ Limited human — failed Phase 2 for obesity | Returning to Cat. 1 |
|
$100–$300 |
| 5-Amino-1MQ NNMT inhibitor (small molecule) |
|
✓ Mostly preclinical | Research only |
|
$100–$250 |
| MOTS-c Mitochondrial peptide for metabolism |
|
✓ Mostly preclinical — mitochondrial peptide | Returning to Cat. 1 |
|
$150–$400 |
Sexual Health
Peptides that act on central arousal pathways or hormonal regulation. PT-141 is the only peptide in this category with full FDA approval.
| Peptide | Expected Results | Evidence | Status | Side Effects | Cost/Mo |
|---|---|---|---|---|---|
| PT-141 Bremelanotide, melanocortin agonist |
|
✓✓✓✓ Strong clinical — FDA-approved as Vyleesi | FDA-approved (Vyleesi, 2019) |
|
$200–$500 |
| Kisspeptin GnRH-stimulating neuropeptide |
|
✓✓✓ Early clinical — reproductive endocrinology trials | Research only; active clinical trials |
|
$200–$500 |
Skin & Cosmetic
Peptides used for collagen synthesis, skin rejuvenation, and cosmetic improvement.
| Peptide | Expected Results | Evidence | Status | Side Effects | Cost/Mo |
|---|---|---|---|---|---|
| Collagen Peptides Hydrolyzed collagen (types I, II, III) |
|
✓✓✓ Early clinical — multiple supplement RCTs | Dietary supplement; available OTC |
|
$20–$60 |
| GHK-Cu Copper peptide for skin and collagen |
|
✓✓ Limited human — small skin studies + animal | Returning to Cat. 1; OTC topical available |
|
$50–$300 |
| Melanotan II α-MSH analog — injectable tanning peptide |
|
✓ Limited — small trials, no FDA approval | ⚠ Not FDA-approved; grey market only |
|
$30–$60 |
Cognitive & Sleep
Peptides with reported nootropic, anxiolytic, neuroprotective, or sleep-regulating properties.
| Peptide | Expected Results | Evidence | Status | Side Effects | Cost/Mo |
|---|---|---|---|---|---|
| Semax Synthetic ACTH analog, neuroprotective |
|
✓✓✓ Early clinical — approved in Russia, some clinical data | Returning to Cat. 1; approved in Russia/Ukraine |
|
$80–$250 |
| Selank Tuftsin analog, anxiolytic nootropic |
|
✓✓ Limited human — approved in Russia, limited Western data | Returning to Cat. 1; approved in Russia |
|
$80–$250 |
| DSIP Delta sleep-inducing peptide |
|
✓ Mostly preclinical — 1980s studies, mixed results | Research only |
|
$100–$250 |
Immune & Longevity
Peptides that modulate immune function, support antimicrobial defense, or target aging-related cellular pathways.
| Peptide | Expected Results | Evidence | Status | Side Effects | Cost/Mo |
|---|---|---|---|---|---|
| Thymosin Alpha-1 Immune modulator, T-cell enhancer |
|
✓✓✓✓ Strong clinical — approved in 30+ countries | Returning to Cat. 1; approved as Zadaxin (35+ countries) |
|
$200–$500 |
| LL-37 Human cathelicidin antimicrobial peptide |
|
✓✓ Limited human — Phase I/II wound + melanoma | Research only |
|
$150–$400 |
| Humanin Mitochondrial cytoprotective peptide |
|
✓ Mostly preclinical — no human intervention trials | Research only |
|
$200–$500 |
| Epitalon Tetrapeptide for telomerase/pineal |
|
✓ Mostly preclinical — single research group | Research only |
|
$100–$300 |
The Regulatory Landscape
Peptide regulation in the United States is complex and has shifted significantly between 2023 and 2026.
FDA-Approved Peptide Drugs
A small number of peptides have completed the full FDA approval process:
- Bremelanotide (Vyleesi) — Approved 2019 for HSDD in premenopausal women
- Tesamorelin (Egrifta SV) — Approved 2010 for HIV-associated lipodystrophy
- Sermorelin (Geref) — Previously approved for GH deficiency diagnosis; brand discontinued, available via compounding
- Semaglutide, tirzepatide, liraglutide — GLP-1 receptor agonists (covered in the GLP-1 section)
The Category System & the 2024–2026 Shift
In late 2023, the FDA placed 19 widely used peptides on its Category 2 list, effectively prohibiting compounding pharmacies from preparing them. The stated rationale was insufficient safety data, risk of immunogenicity, and concerns about peptide-related impurities.
This decision was controversial. Clinicians, compounding pharmacy groups, and patient advocates argued that the restrictions lacked specific safety signals and pushed patients toward unregulated gray-market sources.
On February 27, 2026, HHS announced that approximately 14 of the 19 restricted peptides would be reclassified back to Category 1, restoring legal access through licensed compounding pharmacies. The formal updated list has not yet been published as of March 2026.
"Research Chemicals"
Many peptides sold online are labeled "for research purposes only." This means the compounds have not completed FDA approval, and sellers avoid regulatory oversight by not marketing them for therapeutic use. In practice, a significant number of purchasers use these products therapeutically — carrying real risks: research-grade peptides are not manufactured under pharmaceutical GMP standards, may contain impurities or incorrect dosages, and there is no regulatory recourse if a product is contaminated.
WADA & Athletic Drug Testing
WADA prohibits numerous peptides under Peptide Hormones, Growth Factors, Related Substances, and Mimetics (Section S2 of the Prohibited List). This includes all GH secretagogues, BPC-157, TB-500, and others. Athletes subject to drug testing should consult the current prohibited list before using any peptide.
The information on this page is provided for educational and informational purposes only. It does not constitute medical advice, diagnosis, or treatment recommendations. No doctor-patient relationship is created by reading this content.
Peptides described on this page include FDA-approved medications, investigational compounds, and unregulated research chemicals. Many have not been evaluated by the FDA for safety, efficacy, or quality. The inclusion of any peptide does not imply endorsement or a suggestion that it is safe or appropriate for any individual.
Always consult a licensed healthcare provider before using any peptide or medication. Self-administration of injectable compounds carries risks including infection, dosing errors, allergic reactions, and unknown long-term effects.
Evidence descriptions and regulatory statuses reflect publicly available data as of March 2026 and may change. Cost ranges reflect reported pricing from US-based compounding pharmacies and telehealth providers; actual costs vary by provider, dosage, and region.
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