Peptides are grouped here by the biological systems they primarily interact with. Every entry includes an evidence-status indicator — because "category" says nothing about how well-studied or safe a given peptide actually is.

Figure 3. The six major peptide categories covered in this guide.
Figure 3. The six major peptide categories covered in this guide.

Metabolic Health & Weight Management

This category includes some of the most clinically validated peptides in existence. Several mimic natural gut hormones that regulate appetite, blood sugar, and digestion.

✓ FDA-Approved — Strong Human Clinical Evidence

GLP-1 Receptor Agonists (Semaglutide, Liraglutide, Dulaglutide)

Mimic glucagon-like peptide-1, a natural gut hormone that slows digestion, increases insulin release after meals, and signals fullness to the brain. FDA-approved for type 2 diabetes and chronic weight management.

✓ FDA-Approved — Strong Human Clinical Evidence

GLP-2 Analogs (Teduglutide)

Target intestinal health and gut lining integrity. FDA-approved for short bowel syndrome.

● Limited Human Evidence

AOD-9604

A modified fragment of human growth hormone investigated for fat metabolism. No FDA approval for weight loss; human efficacy data remains limited.

○ Animal Studies Only

5-Amino-1MQ & MOTS-C

Experimental compounds studied in preclinical models for cellular energy metabolism and insulin sensitivity. No completed human clinical trials.

Tissue Repair, Injury & Recovery

The most heavily marketed benefit area — and the one with the largest gap between animal research and confirmed human results. A 2026 review in the Musculoskeletal Journal of Hospital for Special Surgery specifically cautioned sports medicine providers against recommending these peptides.

✕ Not FDA-Approved — Often Sold as Research Chemical

BPC-157 (Body Protection Compound-157)

Animal models show enhanced blood vessel formation and faster healing in tendon, ligament, muscle, and nerve injuries. No high-quality clinical evidence in humans. No large controlled trials. Prohibited under WADA rules.

✕ Not FDA-Approved — Often Sold as Research Chemical

Thymosin Beta-4 / TB-500

Studied for cell migration and wound healing in animal research. Human clinical data lacking. Explicitly listed among growth factors prohibited by WADA.

Growth Hormone Optimization

These peptides stimulate your pituitary gland to release more of your own growth hormone (GH), rather than introducing synthetic HGH directly.

✓ FDA-Approved — Narrow Indication

Tesamorelin

FDA-approved specifically for reducing excess abdominal fat in people with HIV-associated lipodystrophy. Not approved as a general anti-aging or fat-loss product.

● Limited Human Evidence

Sermorelin / Ipamorelin / CJC-1295 / GHRP-2 / GHRP-6

Growth hormone secretagogues studied for triggering GH pulses. None FDA-approved for general use. As a class, banned under WADA rules for competitive athletes. May reduce insulin sensitivity.

Note on Growth Hormone Secretagogues and Sports

Growth hormone-releasing peptides and secretagogues are included on the World Anti-Doping Agency's Prohibited List — regardless of whether a physician recommends them. WADA enforces a strict liability standard.

Longevity, Cellular Health & Immunity

✓ Well-Studied — Multiple Human Studies

Glutathione & NAD+

Well-understood molecules with established roles in cellular energy production, DNA repair, and antioxidant defense. Clinical trial evidence for specific anti-aging marketed outcomes is still developing.

○ Animal Studies Only

Epithalon / FOXO4-DRI

Experimental synthetic peptides in early laboratory or animal research stages. None have human clinical evidence supporting specific health claims.

Cognitive & Neurological Support

● Limited Human Evidence

Semax / Selank / DSIP

Peptides with regional clinical use history (primarily Russia) for cognitive and anti-anxiety effects. Not FDA-approved in the United States. U.S.-based clinical trial data is limited.

Skin, Hair & Aesthetic Support

✓ Well-Studied — Multiple Human Studies

GHK-Cu (Copper Peptide) & Collagen Peptides

Topical GHK-Cu has reasonable supporting research for improving skin moisture, elasticity, and fine lines. Note: Injectable GHK-Cu was FDA-banned in September 2023 due to impurities in compounded versions. Topical formulations were not affected.

✓ FDA-Approved

PT-141 / Bremelanotide (Vyleesi)

FDA-approved for hypoactive sexual desire disorder in premenopausal women. Compounded versions sold outside this approved context lack the same quality oversight.