Can cholesterol get too low, and could that affect testosterone, hormones, or brain function?

Cholesterol is necessary for membranes and steroid hormones, but that does not mean a high circulating LDL level is necessary for normal function. Cells can synthesize cholesterol and regulate uptake. In the randomized DESCARTES study, substantial LDL lowering with evolocumab did not produce an adverse steroid-hormone signal, even in analyses of very low achieved LDL. This argues against the simple claim that lowering LDL inevitably deprives the testes or adrenal glands of the raw material they need.[1]

The EBBINGHAUS randomized substudy also found no significant cognitive disadvantage with evolocumab over a median 19 months, and subsequent follow-up provides additional reassurance. These results concern particular treatments and populations, not every cause of a low cholesterol result. Unexpectedly low cholesterol during illness or poor nutrition deserves a different assessment. Nor do reassuring safety findings mean every low-risk person benefits from aggressive medication. Treatment intensity should follow cardiovascular risk and tolerability, rather than either fear of all low LDL values or a competition to reach zero.[2][3]