Mythbusters.

“Animal studies prove it works in humans.”

Animal and cell studies are useful for mechanism and hypotheses, but routinely fail to translate. Differences in dosing, physiology, and study quality mean an effect in rodents may be smaller, absent, or harmful in people. Preclinical ≠ proven.

“Research peptides are automatically safe because they're peptides.”

'Peptide' is a chemical category, not a safety category. Some peptides are well-characterized approved drugs; many research compounds have little or no human safety data at all.

“Higher purity means sterile and safe.”

Purity is a chemistry measure: the fraction that is the intended molecule. It says nothing about sterility, endotoxin contamination, correct identity, or clinical safety. A '99% pure' label answers one narrow question.

“If it's natural or endogenous, it has no risks.”

Many peptides occur naturally in the body, but supraphysiologic doses, impure preparations, and unstudied long-term use all carry risk. 'Natural' does not mean risk-free.

“If influencers or athletes use it, it must work.”

Popularity and anecdote are not evidence. Visible use says nothing about whether a compound does what's claimed, or whether it's safe.

“All GLP-1 drugs are the same.”

They differ in which receptors they engage (GLP-1 alone vs. dual or triple agonists), in pharmacokinetics, and in their evidence base. They are related, not interchangeable.

“More growth hormone is always better.”

Growth-hormone signalling is tightly regulated; more is not simply better and can carry real risks. Secretagogues alter the body's own release rather than supplying a 'more is better' dial.

“Peptides aren't drugs.”

Pharmacologically active peptides used to affect the body are drugs in every meaningful sense, and many are regulated as such. 'Research-use-only' labeling reflects regulatory status, not harmlessness.

“A Certificate of Analysis proves it's safe to use.”

A COA reports batch chemistry (identity, purity). It is not evidence of sterility, clinical safety, or efficacy, and it does not make a research compound approved for human use.

“Compounded semaglutide is the same drug as Ozempic.”

It is not the approved product. Compounded versions are not made to the same manufacturing standard, and some have used salt forms (semaglutide sodium or acetate) rather than the approved free base, with different stability and absorption. The clinical trial evidence attaches to the approved product, not to a compounded copy of it.

“Adding more bacteriostatic water makes the dose weaker.”

It changes the concentration, not the amount of peptide in the vial. More water means each syringe unit holds less, so the same target amount simply spans more units on the barrel. The total in the vial is fixed the moment it is manufactured. This confusion is the single most common reconstitution error.

“Units on an insulin syringe are a dose.”

A unit on a U-100 syringe is a volume: one unit is 0.01 mL. How much peptide sits in that volume depends entirely on the concentration you mixed. Ten units of one preparation and ten units of another can differ by an order of magnitude.

“IU and mg are interchangeable.”

IU measures biological activity, mg measures mass, and the conversion between them is specific to one compound and one reference standard. Somatropin has an established IU-per-mg ratio; that ratio does not transfer to a different peptide, and for most research peptides no IU standard exists at all.

“Peptides can't really be counterfeited, it's too niche.”

Unregulated supply chains are exactly where substitution, underfilling, and mislabeling happen, because there is no lot release testing and no recall mechanism. Mass spectrometry confirms a molecular weight, which an analogue of similar mass can also satisfy.

“If it's sold openly online, it must be legal to use.”

Availability is not legality. Most of these compounds are sold as research chemicals explicitly not for human use, which is a regulatory posture the seller adopts, not a statement about the buyer's position. Some are also controlled substances or banned in sport.

“GLP-1 drugs destroy your muscle.”

Roughly a quarter to a third of the weight lost is lean mass, which is broadly what happens with caloric restriction by any means, not something unique to these drugs. It is a real consideration that resistance training and adequate protein address, not a reason the drugs are uniquely harmful.

“You can tell a peptide has gone bad by looking at it.”

Cloudiness, particulates and dark discolouration do indicate a problem, so those are worth acting on. But the reverse does not hold: oxidation, deamidation and fragmentation all proceed invisibly, and a solution that looks perfectly clear can have lost substantial activity.