Peptides 101 — what they are, what they aren't, and what to ask

Peptide therapy has gone from underground to mainstream in less than two years. The marketing is loud; the data is mixed. Here's the version a clinician would tell you.

What's actually in the bottle

A peptide is a short chain of amino acids — same building blocks as proteins, just smaller. The most common ones in aesthetic and wellness practice (BPC-157, GHK-Cu, semaglutide, tirzepatide) all work through different mechanisms.

What the evidence supports

• Semaglutide / tirzepatide — solid clinical trials for weight management and glycemic control.
• GHK-Cu (copper peptides) — small studies on skin and wound healing.
• BPC-157 — anecdotal in humans; promising in rats; the FDA hasn't blessed it.

Treat anything that promises weight loss, muscle growth, AND skin tightening in one bottle as marketing.

What to ask before you start

1. Where is this compounded? You want a 503A or 503B pharmacy, not an unregulated source.
2. Who is monitoring? A clinician should review labs at baseline and every 3 months.
3. What's the off-ramp? "Stop one day, gain it back the next" plans are a red flag.

A good med spa will walk you through the same questions and write you a transparent plan you can take to a second opinion.