I have recently been prescribed Testim Gel also. My gynae consultant said the tube should last 7-10 days, - (the blob should be the size of a generous marrowfat pea to manage this!), and I was told to rub it on my inner thighs, although I use my outer thighs, as I also have to fit 3 sachets of sandrena oestrogel to apply, too!! I have read somewhere that the gels have to be rubbed onto fatty areas covered by shorts - as a guide. This works out at roughly a tenth of the male dose, which I've read elsewhere to give same info. Essentially, you should tell by how you feel as a result of taking it, she said. (Nb, any consequences of overdosing wouldn't be evident until 3 months after starting on it though).
I am 42, and started perimenopause at 38. Ovaries etc in tact.
Hope that helps.