Lyophilised (freeze-dried)

Lyophilisation, also known as freeze-drying, is the industry-standard method for preparing peptides for long-term storage. The peptide solution is rapidly frozen and then placed under high vacuum, causing the water to sublime directly from solid to vapour without passing through a liquid phase. The resulting powder is fluffy, white, and stable for years when kept at -20 °C in a sealed vial. Most research peptides ship lyophilised because the form is far more stable than aqueous solutions, easier to weigh accurately, and easier to ship internationally without a cold chain.