SAMA HOOLE: Every memory you form needs [cholesterol] to build the synapse that keeps the memory. Your brain is sixty percent fat, most of it cholesterol.

Testosterone is made from cholesterol.

Oestrogen is made from cholesterol.

Cortisol is made from cholesterol.

Vitamin D is made from cholesterol.

The bile acids that digest your dinner are made from cholesterol.

Progesterone, which holds a pregnancy together, is made from…

— Sama Hoole (@SamaHoole) July 29, 2026

Testosterone is made from cholesterol.

Oestrogen is made from cholesterol. Cortisol is made from cholesterol. Vitamin D is made from cholesterol. The bile acids that digest your dinner are made from cholesterol. Progesterone, which holds a pregnancy together, is made from cholesterol. Every cell membrane in your body is built with it. Every nerve is insulated by myelin, which is mostly it. Every memory you form needs it to build the synapse that keeps the memory. Your brain is sixty percent fat, most of it cholesterol. Breast milk is loaded with it, because no infant brain grows without it. Handed the job of designing the first food a human ever eats, nature put cholesterol at the heart of it. Eat less, and the liver makes more. Because the body will not run without it. In 1977, we declared war on it. Male testosterone has fallen ever since. Vitamin D deficiency went from rare to routine. One adult in three over fifty now takes a daily pill to strip out the one thing every cell above is fighting to keep. The war is going beautifully.