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What Are Peptides? A Plain-English Guide for Biohackers
Peptides are short chains of amino acids that act as precise signals in the body. Here is what they are, how they differ from drugs and proteins, and why the biohacking community is paying so much attention.
Biohack Lab HQ Editorial Team
The short version
A peptide is a short chain of amino acids, typically between two and about fifty residues long. String more amino acids together and you get a protein. Break a protein apart and you get peptides. What makes peptides interesting is that many of them act as *signaling molecules* — they tell cells to grow, to repair, to release a hormone, to calm an immune response.
Your body already produces thousands of peptides. Insulin, oxytocin, glucagon, and growth hormone releasing hormone are all peptides. The therapeutic and research peptides you hear about in the biohacking community are mostly synthetic versions of naturally occurring signals, or novel sequences engineered to bind a specific receptor.
Why peptides matter for biohackers
Three properties make peptides unusually appealing as tools for self-optimization:
- Specificity. A well-designed peptide binds a specific receptor and triggers a narrow response. Fewer off-target effects than a small-molecule drug.
- Short half-life. Most peptides are broken down quickly, which limits long-term accumulation.
- Physiological scale. Doses are measured in micrograms or milligrams and often mimic signals your body already produces.
The usual biohacking categories are healing peptides (BPC-157, TB-500), growth hormone secretagogues (CJC-1295, ipamorelin), cognitive and neuroprotective peptides (Selank, Semax), and metabolic peptides (GLP-1 agonists like semaglutide and tirzepatide).
What peptides are not
Peptides are not magic, and they are not universally safe. Many of the most-discussed research peptides are not FDA-approved for the uses people actually run them for. Manufacturing quality varies wildly across sources. And the human dose-response data behind community protocols is often thinner than enthusiasts admit.
The goal of this publication is to take peptides seriously without losing sight of either the science or the risks. Every explainer we publish points back to primary sources so you can form your own view.
What to read next
If this is your first exposure to the space, start with our explainer on why people biohack in the first place, then move on to our beginner-friendly protocol framework before picking any specific compound.
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