I'll start with hormone supplements since I've heard that messing with the endocrine system is fraught with peril.
First up: Pregnenolone.
Why Supplement Hormones for ME/CFS?
Personally, my pregnenolone levels were one of the lowest of all my hormone levels when tested in December. The lab's reference range is 13 to 208 ng/dL. (The reference range for males is 10-200). (Citation) Mine was a mere 23 - in the bottom 5%.
What is Pregnenolone?
Risks / Concerns
I have also read that weening off of Pregnenolone supplementation can cause depression.
I have concerns about increasing any "steroid" as steroids tend to decrease immune response. I am not certain, however, if this applies to "steroid hormones." It turns out, this is a very complex question with no clear answers. Thus far, only animal studies have been conducted on this topic, but those studies found that steroid hormones actually boost immune response.
I also worry that the increased pregnenolone will convert to female hormones such as estrogen and progesterone. Once inside my body, how do I know which hormones it will convert into? On the other hand, this website claims that that concern is unfounded.
Other sources making a strong case for the benefits of pregnenolone supplementation are here, and here.
For what it's worth, pregnenolone is sold as an over the counter supplement. Anyone can take it in any amount, which tells me it's side effects can't be too harmful. Right...?
On the other hand, pregnenolone is typically sold in maximum quantities of 50mg, and several sources state that the correct dose is a mere 5 to 30mg, with frequent "holidays" to give your body time to start anew. This doctor insists that the correct dosage is only 1-5mg, and that higher dosages are unsafe, but he doesn't provide any citations to research. The bottom line is, there is no consensus.
Pregnenolone is supposed to be taken first thing in the morning, before a meal.
If I continue to take it for more than, say, one year, I will begin regularly testing my levels of dihydrotestosterone, to ensure that it is does not enlarge the prostate.