Marker

The size of the threat detector on MRI. Long-term users had a larger right amygdala than non-using weightlifters, alongside weaker functional coupling between it and the regions that are supposed to regulate it.

Counts the actual number of artery-clogging particles. A better read on risk than LDL-C when the two disagree.

How much mineral is packed into bone. In men it is maintained mostly by ESTRADIOL, which is why crushing oestrogen has a skeletal cost that takes years to show up.

How thick the outer layer of the brain is, measured on MRI. It thins with normal ageing and faster in several dependencies. In steroid users the thinning is regional, and it is concentrated in exactly the areas that handle inhibition.

The kidney's signal telling marrow to build red cells. Androgens raise it, and it is the upstream cause of the haematocrit rise.

The share of blood volume made of red cells. Thicker blood carries more oxygen and clots more easily, and this is the single most reliably moved number on cycle.

Oxygen-carrying protein in red cells. Moves with haematocrit and is the second half of the same reading.

The protective lipid fraction. Oral 17-alpha-alkylated steroids can cut it by half or more within weeks, and it is the fastest-moving marker of cardiovascular cost.

The fraction that deposits into vessel walls. Rises on most androgens and sharply on orals.

Tracks prostate activity and size. Useful mostly as a trend in men over forty.

Beats per minute at rest. A cheap daily read on sympathetic tone, and usually the first number to move when something is pushing the nervous system.

Peak arterial pressure. Rises through water retention, thicker blood and vessel stiffening, and it is cheap to check at home weekly.

The carrier protein for thyroid hormone. When it falls, TOTAL T4 and T3 read low while the free, active hormone is unchanged, so the thyroid looks broken on paper when it is not.

Circulating fat. Moves with diet and insulin sensitivity as much as with any compound, which is why it needs reading alongside the rest of the panel.