How We Rate Peptide Vendors

The Short Version

Every vendor gets a star rating out of 5. That rating combines five things we look at — and one safety rule that can cap the score for vendors who can't prove their products were tested by an independent lab.

We rate vendors against each other within the research-peptide market, not against pharmacy-grade pharmaceutical companies. A 3-star vendor here is "functional with the gaps that everyone in this space has," not "mediocre." A 4-star vendor is genuinely best-in-class.

The Five Things We Look At

Each vendor is scored 0–10 on each dimension, then combined using these weights.

What the 0–10 Scores Actually Mean

Sub-scores are anchored to the research-peptide market — not to a hypothetical pharmaceutical-grade ideal. So "7" doesn't mean "good in the abstract" — it means "typical for this category, which has its known gaps."

The Safety Rule — A Cap for Unverified Labs

If a vendor doesn't publish verifiable third-party lab testing — either explicitly admits in-house testing only, or claims testing they can't actually show you — their final score gets capped. But the cap isn't a flat number. It depends on what other reassurance signals exist.

A brand-new vendor with no labs and no reviews gets capped harder than an established vendor with thousands of satisfied customers — even if neither can prove their testing. Reputation and tenure earn some headroom.

Untested vendors can never look exceptional — but they can still look functional if they've earned community trust over time.

When you see a card with ⚠ Capped, the score you're looking at is below what the raw formula would have produced. When you see a muted "Testing not independently verified" note, the gate fired but their raw score was already below the cap, so the cap didn't change anything — it's just informational.

About Consumer Reviews

Where customer reviews exist, we show them too — separately from our editor score, and adjusted for sample size. Five glowing reviews don't beat a hundred mixed-but-positive ones.

We do this with a technique called Bayesian smoothing: until a vendor has built up enough reviews to be statistically meaningful, their average is pulled gently toward 3.5 (the prior we assume for an unknown vendor). Once they have plenty of reviews, their own number takes over.

Example. Three 5-star reviews → displayed as about 4.15, not 5.0. 200 reviews averaging 4.5 → displayed as ~4.46 — barely budged, because we have enough data to trust them.

When reviews on different platforms sharply disagree (e.g., Trustpilot 4.8 but Sitejabber 2.7), we'll flag it in the vendor's notes. That kind of split often indicates review manipulation.

A Worked Example

Say "Acme Peptides" gets these sub-scores from us:

If Acme had no third-party testing, the gate would fire. Their cap would be calculated: 6.0 base + 1.0 (4–7 years tenure) + 0.5 (decent shipping) = 7.5 / 10 → 3.75 ★. Since their raw is 7.30, the cap doesn't reduce them — but the muted "Testing not independently verified" note would still appear on the card.

What We Don't Measure (and You Should Check Yourself)

• Whether peptides are right for you. That's between you and a qualified medical professional.
• Legal status in your state or country. Rules vary and change. Verify before ordering.
• Specific batch results. We rate the vendor's published process. The lot you receive is yours to inspect.
• Real-time stock or pricing. Our scores don't update on every promo; check the vendor directly.