Free tools

All tools

Everything you need for your protocol, in one place. Free, no signup, instant results.

Reconstitution calculator

How many units to draw into the syringe based on your vial and bacteriostatic water.

Semaglutide calculator

Semaglutide and tirzepatide with the full titration schedule.

Peptide comparator

Compare two peptides side by side: route, dose, evidence and more.

Stack compatibility

Can I combine these two peptides? Instant verdict.

Peptide library

48 peptides with dose, half-life and full profile.

Clearance calculator

How long a peptide takes to clear your system, based on its half-life.

Cost per mg calculator

How much each mg and each dose costs you, based on what you paid.

TRT dose calculator

Calculate mg, mL, and syringe units per testosterone injection based on your weekly dose and concentration.

Quiz: do I need a TRT test?

8 quick questions about common symptoms — not a diagnosis, helps you decide if a blood test is worth it.

PeptiBrain is a personal tracking diary. It is not medical advice and does not replace a healthcare professional, and it does not recommend doses: it records what you decide. Testosterone replacement therapy (TRT) is a prescription hormonal treatment that requires diagnosis and ongoing medical follow-up; never start or adjust it on your own. Always consult a professional before making decisions about your health.