You’ve heard the word everywhere — on podcasts, in your dermatologist’s office, from that friend who swears by her “peptide protocol.” But what actually are peptides? Are they drugs? Supplements? Hormones? Something your body already makes? The answer is: it depends on the peptide. Here’s the no-jargon breakdown.
A peptide is a short chain of amino acids — typically between 2 and 50. Your body is already full of them. Insulin is a peptide. Oxytocin (the “love hormone”) is a peptide. Your body uses peptides as signaling molecules — tiny messengers that tell cells what to do: repair tissue, release hormones, regulate metabolism, modulate immune responses, or produce collagen.
Peptide therapy uses synthetic versions of these natural signaling molecules (or novel peptides designed to mimic them) to trigger specific biological responses. Unlike hormones that replace what your body isn’t making, many peptides signal your body to produce and regulate its own hormones more effectively.
| Category | What It Means | Examples |
|---|---|---|
| FDA-Approved Drugs | Fully tested, regulated, prescribed for specific conditions | Semaglutide (Wegovy/Ozempic), Tirzepatide (Zepbound), PT-141 (Vyleesi), Tesamorelin (Egrifta) |
| Compoundable Peptides | Can be produced by licensed pharmacies with a prescription | Sermorelin (Category 1), others under PCAC review |
| Research Peptides | Sold as research chemicals, not for human use. Used off-label by some practitioners | BPC-157, KPV, Selank, DSIP, Epitalon, MOTS-C |
| Cosmetic/Supplement Peptides | Available over-the-counter in serums, supplements | GHK-Cu serums, SNAP-8 serums, collagen peptides |
Injectable (subcutaneous): The most common route for therapeutic peptides. Uses tiny insulin needles (29-31 gauge). Goes into the fat layer just below the skin. Most women say it’s far less painful than expected. See our full injection guide.
Topical: Serums and creams applied to skin or scalp. GHK-Cu and SNAP-8 are both effective topically. No needles, no prescription needed for cosmetic formulations.
Intranasal: Nasal sprays. Selank and Semax are administered this way, bypassing the digestive system and accessing the brain directly.
Oral: Some peptides survive digestion — oral BPC-157 for gut health, collagen peptides for skin and joints, oral semaglutide (Rybelsus, by prescription). See our oral vs injectable guide.
The most common use cases in our community: weight management (semaglutide, tirzepatide, retatrutide), skin and hair (GHK-Cu, glutathione, SNAP-8), gut health (BPC-157, KPV), hormonal support during perimenopause (CJC-1295/Ipamorelin, kisspeptin-10), anxiety and sleep (Selank, DSIP), sexual wellness (PT-141), recovery and healing (BPC-157, TB-500), longevity and anti-aging (NAD+, Epitalon), and autoimmune conditions (Thymosin Alpha-1, KPV).
Safety varies by peptide. FDA-approved peptides (semaglutide, tirzepatide, PT-141, tesamorelin) have undergone extensive clinical testing with established safety profiles. Research peptides (BPC-157, KPV, Selank) have less human safety data — most evidence comes from preclinical studies and clinical observation. Topical peptides (GHK-Cu serums) carry the lowest risk due to minimal systemic absorption. Always work with a qualified provider for injectable peptides.
FDA-approved peptides are legal with a prescription. Research peptides are sold legally as 'not for human use' — a gray area that the July 2026 PCAC meeting may clarify for seven specific peptides. Topical peptide cosmetics and collagen supplements are fully legal and available over-the-counter. The legal landscape is actively evolving in 2026.
Peptides and anabolic steroids are fundamentally different. Steroids are synthetic versions of hormones (like testosterone) that directly alter hormone levels. Peptides are signaling molecules that instruct your body's own systems to produce hormones, repair tissue, or modulate immune responses. Peptides generally have fewer side effects and don't carry the same risks of hormonal disruption, liver damage, or virilization that steroids do.
Costs range widely. Topical peptide serums: $30-80/month. Oral collagen peptides: $20-50/month. Research peptides (injectable): $50-300/month per peptide depending on the compound. FDA-approved peptides (semaglutide, tirzepatide): $300-1,500/month without insurance. Provider consultations: $150-500 initial, $100-300 follow-up. Lab work: $200-500. Budget for the complete picture, not just the peptide itself.