Thanks for providing another member's experience. I don't see very many guys going down in dose.Don't rely on the so-called direct free testosterone tests. They are useless, and the dose linearity might not be reflected in them. Instead either use equilibrium dialysis or Vermeulen calculated free testosterone. For the latter, measure SHBG and ideally albumin in addition to total testosterone.
Keep in mind that it is common to have transient symptoms of hypogonadism after a significant dose reduction. These can persist for a while, so be mentally prepared in case you have this experience. For encouragement, here is another member's tale, emphasis mine:
Some hypogonadism symptoms are similar to hypothyroid symptoms (low energy/brain-fog/depression). I may be starting Thyroid treatment about the same time I'm transitioning to a lower Test-dose. My life will likely be a roller-coaster for the next few months. When everything settles out I hope to be on a reasonable Test-dose (with reasonable levels) and also have my Thyroid levels optimized so I can get on with life.
For labs, I'm now using a panel I found on Discount Labs. It includes:
Testosterone Free and Total (LC/MS/MS)
E-2 (Ultra Sensitive LC/MS)
DHT (LC/MS/MS)
If I understand the DL website, Free-T is determined using Equilibrium Dialysis (to find the % Free-T) and then this is compared to Total-T to find the actual Free-T value.
This panel normally costs $203 but if you buy all three tests separately it's only $176. Not sure why. I bought the panel but put it on a subscription. Do that and it's only $150.