Peptide Dosing 101

Peptides are measured in micrograms (mcg) or milligrams (mg). Understanding the conversion is essential:

1 mg = 1,000 mcg

Most peptide doses are in the 100–1,000 mcg range (0.1–1 mg). Some peptides like Thymosin Alpha-1 use milligram doses (1.6 mg). GLP-1 agonists like semaglutide use milligram weekly doses (0.25–2.4 mg).

Insulin syringes are marked in "units" (1 mL = 100 units). After reconstitution, each unit mark represents a specific amount of peptide based on your reconstitution ratio.

Most peptides are administered via subcutaneous (SubQ) injection — into the fat layer just beneath the skin. This is not intramuscular injection.

1. Clean the injection site with an alcohol swab 2. Pinch a fold of skin (abdomen, thigh, or upper arm are common sites) 3. Insert the needle at a 45–90° angle (90° for insulin needles) 4. Depress the plunger slowly and steadily 5. Hold for 5 seconds before withdrawing 6. Do not rub the injection site afterward

Rotate injection sites to avoid lipodystrophy (tissue changes from repeated injections in the same spot).

Different peptides have different optimal timing:

Growth hormone secretagogues (GHRP-6, Ipamorelin, CJC-1295, MK-677): Best on an empty stomach. Food — especially carbohydrates and fats — blunts GH release. Wait 20–30 minutes after injection before eating. Common timing: morning (fasted), post-workout, and before bed.

Healing peptides (BPC-157, TB-500): Timing is less critical. Consistency matters more than timing. Once or twice daily at roughly the same times.

Nootropic peptides (Semax, Selank): Morning and early afternoon for cognitive effects. Avoid evening dosing for stimulating peptides like Semax.

Melatonin-related (Epitalon): Evening/before bed to align with pineal gland circadian activity.

There is often a disconnect between published research doses and what community protocols recommend.

Research doses are typically expressed as mg/kg (milligrams per kilogram of body weight) from animal studies. These must be converted using allometric scaling for human equivalence — a complex calculation that many community protocols oversimplify.

Community protocols are based on a mix of allometric scaling, anecdotal experience, and consensus. They are not clinically validated.

On every peptide page on this site, we provide both research-based dosing (from published studies) and community-reported protocols, clearly labeled. Always understand which you are reading.

Regardless of the target dose, the general principle is: start low, assess tolerance, then increase.

For most peptides, begin at 50% of the target dose for the first 3–5 days. If well-tolerated, increase to the full dose. This allows you to identify any adverse reactions at a lower dose before committing to the full protocol.

This is especially important for GH secretagogues (water retention, joint pain can indicate the dose is too high) and GLP-1 agonists (nausea is dose-dependent and improved by slow titration).