[Lotus]

[DHT] WTF good is it?

DHT has use, but too much of it does as you say. DHT even up-regulates estrogen receptors.

Lowering DHT up-regulates the effects of estrogen in the body, and once DHT is converted to aromatase it can't be converted back to E. Are your talking about the study where they castracted rats, which isn't relevant at all.

In the present study, efferent ductule ligation and castration, followed by replacement with testosterone, dihydrotestosterone (DHT) or estradiol was used to investigate the relative importance of circulating and luminal sources of steroid for the modulation of ERα, ERβ and AR in rat efferent ductules. Uni- or bilateral castration and ligation did not affect the expression of ERα and ERβ, but bilateral castration caused down-regulation of AR. Replacement with DHT and testosterone alone or in combination with estradiol caused the recovery of AR expression to control levels. A slight recovery of AR was also observed after estrogen replacement. ERα expression was decreased to nearly undetectable levels after estrogen replacement. 
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2973561/




DHT is a potent androgen and cannot be aromatized to oestrogens, therefore acting as a pure androgen. DHT has been proposed as an androgen replacement therapy, with possible advantages over testosterone in certain circumstances in the ageing population as well as in patients with gynaecomastia and microphallus. A potential advantage of DHT over testosterone as an androgen replacement therapy is the reported and seemingly paradoxically muted effects of DHT on prostate growth. The decreased effect of DHT compared with testosterone on the prostate gland of humans may be due to the decrease in intraprostatic oestradiol levels. The potential beneficial effect of less prostate growth after DHT requires substantiation and, if true, must be balanced against any negative effects that might occur on bone, lipids and sexuality when a pure androgen replaces treatment with an aromatizable androgen.

Dihydrotestosterone: a rationale for its use as a non-aromatizable androgen replacement therapeutic agent.
http://www.ncbi.nlm.nih.gov/pubmed/10332569