Dihydrotestosterone (DHT) – Measurement of DHT levels in the blood (S-DHT)
This test analyzes the levels of dihydrotestosterone (DHT) in serum. DHT is a powerful androgen hormone that is formed from testosterone via the enzyme 5-alpha-reductase and plays an important role in the development of male sexual characteristics. It is particularly active in the skin, hair follicles and prostate.
Important information about DHT and the use of the test
DHT acts mainly locally in tissues rather than in the bloodstream, which means that serum levels do not always reflect the actual biological activity. DHT is therefore not a primary marker for assessing androgen status in adults, and the interpretation of test results can be complex.
Several leading laboratories, including Karolinska, advise against using DHT analysis in the investigation of androgen status in adult men or in the follow-up of testosterone therapy. Furthermore, there is a lack of clear reference values for adults.
When might a DHT test be warranted?
Measurement of S-DHT is mainly used for certain specific medical conditions, and usually at the initiative of specialist physicians, such as pediatric endocrinologists. Examples of indications where the test may be relevant:
- 5α-reductase type 2 deficiency: A congenital enzyme defect in which testosterone is not converted to DHT in sufficient quantities.
- Treatment with DHT-containing cream: Sometimes used for micropenis in boys, where levels are monitored to avoid overdose.
- Investigation of DSD (Disorders of Sex Development): If abnormalities in sexual development are suspected, DHT measurement can be part of a broader investigation.
The DHT test should not be used for:
- Assessment of androgen status in adult men
- Follow-up of testosterone treatment
- General health checks or investigations of hair loss/prostate enlargement without a clear medical reason indication
