Purity you can verify

A peptide is a short chain of amino acids. That is the whole definition. Amino acids are the same twenty-odd building blocks your body uses to make every protein it owns, and a peptide is a small run of them joined end to end, usually somewhere between 2 and 50 units long.

Size is the line that separates a peptide from a protein, and it is a soft line rather than a hard one. Chains above roughly 50 amino acids get called proteins, and they fold into large three-dimensional shapes with pockets and hinges. Below that, chains are small enough to stay relatively simple in shape. That has practical consequences: smaller molecules are easier to synthesise to a consistent standard, easier to characterise on analytical equipment, and easier to reproduce batch after batch. BPC-157 is 15 amino acids. Somatropin, at 191, is a protein and behaves like one, which is why it is handled and stored differently from everything else on this page.

Peptides work by signalling rather than by force. Cells carry receptors on their surfaces, and a receptor is shaped to recognise one particular molecule the way a lock recognises one key. When a peptide binds its receptor it triggers a cascade inside the cell: enzymes activate, genes switch on or off, the cell changes what it is doing. This is why dose and timing matter more than volume. A peptide is an instruction rather than a raw material your body consumes. Tesamorelin does not build anything itself, it tells the pituitary to release growth hormone. GHK-Cu does not construct collagen, it signals fibroblasts to make more of it.

Most peptides cannot be swallowed, and the reason is mechanical. Your stomach and small intestine are full of proteases, enzymes whose entire job is to cut peptide bonds and reduce dietary protein into free amino acids. A peptide taken orally is treated as food. Whatever survives that then passes through the liver before reaching general circulation, where a further share is metabolised on the first pass. Oral bioavailability for most peptides lands in the low single digits or below. Injection and, to a lesser extent, nasal delivery exist to route around that.

Half-life is the last piece worth understanding. It is the time taken for blood levels to fall by half, and for peptides it ranges from a few minutes to several days depending on the molecule and how it has been modified. Native GHRH survives around 7 minutes. Tirzepatide sits at roughly 5 days, which is what makes weekly dosing possible. Short half-life means frequent administration or a deliberately pulsed protocol. Long half-life means convenience and a steadier level, and also that a mistake takes longer to clear.

Most of the evidence behind these compounds is preclinical. That means cell cultures and animal models, sometimes supported by small human trials with dozens rather than thousands of participants. There are exceptions worth naming: tirzepatide and somatropin have full regulatory approval and large trial programmes, and tesamorelin has phase III data behind it. For a great deal of the rest, including BPC-157, TB-500 and MOTS-C, the honest position is that mechanisms look plausible and early results look interesting, and that neither of those is the same as proof in humans. When we cite a study on this site we say what kind of study it was and how many people were in it.

In South Africa, none of these products holds SAHPRA registration as a medicine, and we do not present them as approved treatments or make claims about diagnosing or curing anything. Nobody should begin a peptide protocol without a healthcare provider who knows their history and can order the relevant bloodwork, particularly for anything touching the growth hormone axis or metabolic control. We sell research-grade compounds with full documentation, we tell you what the evidence does and does not support, and we would rather lose a sale than overstate a study.