Glossary

The terms, in plain English.

Every acronym on this site, explained without the jargon — so you can read a COA or compare vendors without a dictionary. For research use only; nothing here is medical or dosing advice.

Research use only (RUO)

A designation meaning a product is sold for laboratory research, not for human or veterinary use. Everything indexed on this site is discussed on that basis only.

COA (Certificate of Analysis)

A lab document reporting a specific batch’s test results — usually identity and purity. A third-party (independent) COA is far stronger evidence than one the seller issued themselves. Learn more ›

HPLC (purity test)

High-Performance Liquid Chromatography — the test that measures how pure a sample is, usually as a percentage. A purity number only means something when it names the lab and the batch it came from.

Mass spectrometry (identity)

A test that confirms the compound is actually what the label says. Purity without identity is only half the picture — you want both.

Purity %

The share of a sample that is the intended compound, per HPLC. Higher is better, but the lab name and the batch it is tied to matter just as much as the number.

Lot / batch number

The code identifying one production run. Testing and reviews are only trustworthy when they are tied to the exact lot you actually receive.

Third-party testing

Testing done by an independent lab (for example Janoshik or Freedom Diagnostics), not by the seller. Independent results are much harder to fake than a vendor’s own paperwork.

Vial

The sealed glass container a peptide ships in, labeled by its milligram (mg) content. We compare prices by the vial because that is what you actually pay at checkout.

Blend

A single vial that contains more than one compound.

mg vs mcg

A milligram (mg) is 1,000 micrograms (mcg). Labels and prices are given in mg; confusing the two is one of the most common beginner mistakes.

Reconstitution

Mixing a freeze-dried (lyophilized) peptide with a sterile liquid so it can be handled in the lab. Our calculator helps with the arithmetic — it is about handling, not dosing. Learn more ›

Bacteriostatic water

Sterile water with a small amount of preservative, commonly used to reconstitute peptides in research settings. Learn more ›

Compounded vs brand

Brand-name medicines (e.g. Wegovy, Zepbound) are FDA-approved and made by the original manufacturer. Compounded versions are prepared by licensed pharmacies. This distinction mainly matters on the telehealth side. Learn more ›

GLP-1 receptor agonist

A class of compounds (for example semaglutide, tirzepatide, retatrutide) studied in metabolic research. Discussed here only as research compounds — for any medical use, consult a licensed clinician. Learn more ›

Trust Score

Our 0–100 score for a vendor, combining price, verification, how recent their COAs are, and screened reviews. It is never for sale. Learn more ›

Verified

A vendor whose batch-tied COAs, review authenticity, and pricing held up under independent checking. It is not a health or safety endorsement, and it can never be bought. Learn more ›

Scam Watch

Our list of vendors with a confirmed, evidence-backed problem — a forged COA, non-delivery, or uncorrected false claims. Every flag shows its specific reason. Learn more ›

Chromatogram

The chart behind an HPLC purity number. A purity figure with no chromatogram to back it is easy to invent — a real COA shows the chart.

Telehealth

Licensed medical care delivered by video or phone. It is where we send every medical question — for example, whether a treatment is right for you. Learn more ›

New to all this? Start with our 5-minute beginner’s guide — it walks you through the handful of things worth understanding before you compare vendors.