Safety reference
Peptide safety: what is known, and what is simply not
Most writing on this subject answers "is it safe?" with reassurance or alarm. The honest answer for many marketed peptides is that nobody knows, because the studies that would establish it have not been done — and that is a different, more useful thing to be told.
Read this first
This page is general information compiled from primary sources. It has not been independently reviewed by a licensed clinician, and it is not medical advice. It does not list contraindications or dosing, because applying either to yourself is precisely the step that requires someone who knows your history. If you think you may be having a medical emergency, contact emergency services.
Where safety information actually comes from
There is a hierarchy here, and where a substance sits in it matters more than any claim made about it.
FDA-approved label
Adverse reactions observed in trials of known size, in a defined population.
Registered human trials
Useful — but read the size. A few dozen participants cannot detect an uncommon harm.
Animal and in-vitro work
Where the literature for most marketed peptides actually sits. Not evidence of human benefit.
Testimonials and forums
Not evidence. Systematically under-reports harm.
FDA's own recurring language about the peptides it has assessed for compounding is worth quoting, because it is the plainest summary available: the agency has identified "no, or only limited, safety-related information" and therefore "lacks sufficient information to know whether the drug would cause harm when administered to humans."
Risks that have nothing to do with the molecule
A substance can be well understood and still be delivered in a way that causes harm. For anything prepared outside a licensed pharmacy, these are the documented failure modes.
Dosing errors
FDA has reported adverse events, some requiring hospitalisation, arising from miscalculated doses — including confusion between millilitres, milligrams and "units". This is the most frequently documented harm in the compounded GLP-1 record.
Contamination and endotoxin
Not one supplier in our catalogue publishes a sterility or endotoxin report for any catalogue item. A purity figure says nothing about either, and neither can be inferred from an HPLC result.
Identity and labelling
Where a certificate shows HPLC purity only, it establishes how much of one thing is present — not that the thing is what the label says. Mass-spectrometry identity data is the check, and it is often absent.
No recall route
If an approved medicine has a problem, there is a mechanism to find out and a mechanism to act. For a product bought outside that system, there is generally neither.
What to ask before starting anything
These are questions a clinic proposing treatment should be able to answer without hesitation. Vagueness on any of them is itself an answer.
- For each substance you are proposing: is it FDA-approved for this use, prescribed off-label, compounded, or investigational?
- What human evidence supports the use you are proposing, and how many people were in those studies?
- If it is compounded, which pharmacy prepares it, and how is that pharmacy licensed?
- What baseline testing do you require before starting?
- What do you monitor during treatment, how often, and what result would make you stop?
- Who do I contact if I have a reaction, and what happens outside office hours?
- What is the plan for stopping — and what typically happens when someone does?
Common questions
Is peptide therapy safe?
The question has no single answer, because "peptides" spans approved medicines with large trial datasets and substances with essentially no controlled human data. For an approved medicine used for its approved indication, the safety profile is documented on the FDA label. For a substance with no approved human indication, there is usually no controlled safety dataset at all — and an absence of reported harm in a small literature is not evidence of safety.
What are the most common side effects?
That depends entirely on the substance. Where an FDA-approved product exists, its label lists adverse reactions observed in trials, and that label is the authoritative source. For unapproved substances no equivalent document exists, which is itself the most important fact about them.
Who should not take peptide medicines?
Contraindications are specific to each medicine and are listed on its label where one exists. This is a determination for a clinician who knows your history, your other medicines and your conditions. We do not publish contraindication lists, because applying one to yourself is exactly the step that requires a clinician.
What extra risks come from products bought outside a pharmacy?
Risks that have nothing to do with the molecule: contamination, endotoxin exposure, incorrect or absent labelling, and dosing errors. FDA has reported adverse events including hospitalisations from patients and clinicians miscalculating doses, driven partly by confusion between millilitres, milligrams and "units".
What monitoring should a clinic do?
Ask. A clinic proposing any prescription medicine should be able to tell you what baseline testing it requires, what it monitors during treatment, how often it reviews, and what result would make it stop. If those answers are vague, that is information.
Take these questions to a clinician
Someone who has evaluated you is the only person who can answer them for your situation.