Peptide Dosing: Why There Is No Standard Dose for Unapproved Peptides

There is no standard dose for unapproved peptides such as BPC-157, TB-500 or MOTS-c, because no one has done the human trials needed to find one. A dose is not a property of a molecule that can be looked up or calculated. It is the result of a long, structured series of studies in people that tests what range is tolerated, which amount gives the best balance of benefit and harm, and how that varies between people.

Searches for “peptide dosage”, “peptide dosage chart” and “peptide calculator” are among the most common on this topic. This guide answers the question behind them: where would a reliable dose come from, and why the numbers circulating online do not meet that standard. It deliberately contains no doses, measurements, schedules or calculations, and InsidePeptides does not publish them for any peptide, approved or not.

The reasons are straightforward. For unapproved peptides, there is no trial-based figure to report, and repeating an untested number would lend it authority it does not have. For approved peptide medicines, a tested dose does exist, but the right dose for a person depends on their condition, other medicines, kidney function, side effects and response, and the label sets out how a prescriber adjusts it. That is a clinical decision, not something a reference website can make. The difference between the two groups is explained in Approved vs Unapproved Peptides.

Finding a dose is one of the main jobs of drug development. The general process is described in Peptide Drug Development and How Clinical Trials Work; the dose-related steps are summarised here.

Before people: animal safety studies

Laboratory and animal studies identify how a compound behaves and the highest exposure that caused no significant harm in each species. FDA guidance explains how developers use those findings, with a deliberate safety margin, to choose a cautious starting dose for the very first human trial in healthy volunteers [1].

Phase 1: dose escalation

Small groups of volunteers receive the starting dose, and later groups receive higher doses only after the safety data from earlier groups have been reviewed. The aim is to learn how the body handles the drug and what range is tolerated, not whether it works. This caution exists because animal data cannot rule out serious reactions in people. In the first-in-human trial of TGN1412 (an antibody, not a peptide), every volunteer who received a single dose developed a severe inflammatory reaction within hours and became critically ill [3]. Events like this are why first doses are kept low and raised only in steps.

Phase 2: dose-ranging

Patients with the target condition are randomly assigned to several different doses, often with a placebo, so that researchers can see how benefit and side effects change as the dose changes. The international guideline on dose-response information, adopted by U.S., European and Japanese regulators, explains why this is needed: historically, some medicines were first marketed at doses later recognised as excessive, sometimes with harmful consequences, and dose-ranging early in development helps avoid building a database of ineffective or excessive doses [2]. Semaglutide's development for obesity included exactly such a randomised, placebo-controlled, dose-ranging phase 2 trial before the large phase 3 programme [6].

Phase 3 and the label

Large randomised trials then test the chosen dose or doses against placebo or existing treatment. If a regulator approves the medicine, the tested dosing, including how to start, how to increase and when to adjust or stop, is written into the prescribing information. The Wegovy label, for example, sets out a gradual dose-escalation schedule and instructions for what to do if side effects are not tolerated [7]. What approval means is covered in What FDA Approval Means.

Most online peptide charts trace back to doses used in rats or mice. Converting those to a human dose is not reliable, for several reasons.

• Scaling by body weight is wrong. Small animals clear drugs much faster relative to their size than people do. Simply multiplying an animal dose by human body weight can give a figure that is far too high, which is why pharmacologists have warned against it [4].
• Better scaling still gives only a starting estimate. Methods based on body surface area, described in the FDA's 2005 guidance and in practice guides, are designed to estimate a cautious first dose for a phase 1 trial [1][5]. The FDA guidance applies a safety factor because of uncertainties such as differences between human and animal receptor sensitivity, and it covers only the starting dose for a first trial in healthy volunteers; it states that it does not address dose escalation or maximum doses, let alone what dose would treat a condition [1].
• Species differ in biology. Receptors, enzymes, immune responses and the way a peptide is absorbed and broken down can all differ between species. A peptide that acts strongly in rats may act weakly, differently or not at all in people (see Human vs Preclinical Research).
• Animal studies test different things. They often use injection routes, injury models and durations that do not match how a product is used by people, and many use a wide range of doses without establishing which one would suit a human condition.

BPC-157 illustrates the problem. Its pharmacokinetics have been described in rats and dogs [8], and a systematic review of its use in orthopaedic sports medicine found that almost all of the evidence came from preclinical studies, with only a single small clinical study [9]. None of that work establishes a human dose.

Online “dosage charts” for peptides such as BPC-157, TB-500, ipamorelin or MOTS-c usually present a confident-looking figure and schedule. When their sources can be traced at all, they tend to come from one of three places: animal studies converted to human figures, personal experience posted on forums or social media, or a seller's marketing material. None of these is a human dose-finding trial.

The human evidence for BPC-157 shows how thin the base is. A systematic review published in October 2026 searched the medical literature and trial registries and found only a few small human studies, all judged to be of poor methodological quality, with the overall certainty of evidence rated very low. The authors concluded that BPC-157 should not be used clinically outside ethically approved, regulated, high-quality trials [10]. The largest of those studies was a retrospective review of knee injections, with no control group [11]. None was a randomised trial designed to find a dose.

Regulators have reached the same conclusion from a safety angle. The FDA lists BPC-157 among bulk substances that may present significant safety risks in compounding, noting a possible risk of immune reactions, complexities with peptide-related impurities, and that it has identified no, or only limited, safety information, so the agency “lacks sufficient information to know whether the drug would cause harm when administered to humans” [12]. Its dated legal history is set out in Is BPC-157 Legal?.

“Peptide calculators” add a further layer. They convert a chosen dose into a volume to draw from a vial, which assumes that the starting figure is valid and that the vial contains exactly what its label says. As the next section explains, neither assumption is safe for unapproved products. A precise calculation applied to an untested figure and an unverified product produces precision without accuracy. Combining several such peptides compounds the uncertainty (see Peptide Stacks).

A guessed dose carries the uncertainty of the figure itself plus every uncertainty about the product and how it is measured.

• Purity and identity. Peptides sold outside the medicine supply chain are not made under pharmaceutical quality controls. A certificate of analysis from the seller is not an independent guarantee (see Peptide Purity and Certificate of Analysis).
• Strength that does not match the label. When researchers bought semaglutide from illegal online pharmacies and tested it, the vials were judged probably substandard or falsified: the measured amount of semaglutide differed from the labelled amount, and the measured purity fell far short of the purity claimed on the label [13]. If the strength is wrong, every calculated dose is wrong.
• Contamination. The same study found bacterial endotoxin in every vial tested [13]. Synthetic peptides can also carry related impurities from manufacture (see Peptide Impurities).
• Measuring errors. In 2024 the FDA warned of adverse events, some needing hospital care, linked to dosing errors with compounded semaglutide. Patients drew up several times the intended amount from multiple-dose vials, and clinicians miscalculated doses. The FDA said confusion between different ways of measuring a dose, unfamiliar syringes and varying product concentrations contributed [14]. A poison control centre separately reported cases of large accidental overdoses of compounded semaglutide, with nausea, vomiting and abdominal pain lasting days [15]. If such errors occur with a medicine that has a tested dose and a prescriber, the risk is greater when the figure itself is a guess.

Semaglutide is an approved medicine, and these problems arose with compounded or illegally sold versions rather than with the approved pens. The same lessons apply even more strongly to unapproved peptides, where neither the product nor the dose has been tested. Compounding rules are explained in Compounded Peptides and the FDA's recent policy in Compounded Semaglutide and Tirzepatide Explained.

For an approved peptide medicine, the dose is set by a licensed prescriber using the label and the person's own circumstances. Useful questions to ask include:

• Is this an FDA-approved product, a compounded product, or something else, and why was that option chosen?
• How will the dose be started and changed over time, and what should prompt a change?
• Exactly how is each dose measured? Is it a prefilled pen, or a vial and syringe, and how exactly do the instructions express each dose?
• Which side effects are expected, which are warning signs, and who should be contacted about them?
• What should happen if a dose is missed or the medicine needs to be stopped?
• How does this medicine interact with other medicines, supplements or health conditions?

Pharmacists can also check how a dose should be measured and whether the product supplied matches the prescription. If a clinic or website offers an unapproved peptide, it is reasonable to ask what human trial evidence supports its use and its dose, and whether it is legally supplied. The answer for most peptides sold online is that no such trial exists (see Are Peptides Legal? and Are Peptides Safe?). Suspected side effects of any medicine can be reported to the FDA's MedWatch programme.

What is the correct dosage for BPC-157?

No tested human dose exists. BPC-157 has no completed controlled human trials, the few human reports are small and of poor quality [10], and the FDA says it lacks sufficient information to know whether it would cause harm in people [12]. Figures quoted online are not based on trials.

Is there a reliable peptide dosage chart?

Not for unapproved peptides. A reliable dose comes from dose-escalation and dose-ranging trials in people [1][2], and those trials have not been done. For approved medicines, the dosing is in the official prescribing information and is applied by a prescriber.

Can you convert an animal peptide dose to a human dose?

Not reliably. Scaling methods exist, but they are designed to pick a cautious starting point for a first human trial, not a treatment dose [1][4], and species differences can make predictions badly wrong [3].

Are peptide calculators accurate?

A calculator can only convert a chosen dose into a volume. It cannot make an untested dose valid, and it assumes the product's strength matches its label, which testing of illegally sold peptides has shown may not be true [13].

Why doesn't InsidePeptides list doses?

For unapproved peptides there is no trial-based dose to report. For approved medicines, dosing depends on the individual and is a decision for the prescriber, guided by the label. Publishing figures would invite the kind of self-measured dosing that has led to reported errors and hospital care [14].

Where can I find the dose of an approved peptide medicine?

In the official prescribing information and from the prescriber or pharmacist, who can explain how it applies to a particular person. Approved peptide medicines are listed in Approved Peptide Medicines.