Pamela, I agree with you about "muscle supplements". They have one certain consequence - your bank balance will decrease. Unless DB has some underlying medical problem their main effect is that he will produce very expensive urine.

I think that Gerry has made a good point about thyroid function - TSH, T3 and T4 are all worked checking out. You could also suggest that DB gets his GP to arrange for tests of thyrotropin-releasing hormone (TRH) as well - basically TRH "tells" the pituitary gland to make TSH.

If anything of concern emerges from these measurements then usually highly-effective treatments are available.