Low DHT affects men and women very differently. In men, it can disrupt sexual development, reduce masculine physical traits, and potentially influence mood. In women, low DHT has minimal impact on health, sometimes causing nothing more than reduced body hair. The consequences depend heavily on when DHT drops: during fetal development, during puberty, or in adulthood.
What DHT Does in Your Body
DHT (dihydrotestosterone) is made when an enzyme called 5-alpha reductase converts testosterone into a more potent form. While testosterone drives the development of internal male reproductive organs, DHT is specifically responsible for forming external genitalia during fetal development and for traits like facial hair, body hair, and prostate growth later in life. Your body produces DHT in several tissues, including the skin, hair follicles, and prostate.
Because DHT is derived from testosterone, low testosterone almost always means low DHT as well. But it’s also possible to have normal testosterone and low DHT if the enzyme that converts one to the other isn’t working properly.
Effects on Male Fetal Development
The most dramatic consequences of low DHT occur before birth. When a genetically male fetus can’t produce enough DHT due to an enzyme deficiency, the external genitalia don’t develop as expected. The internal reproductive structures, which depend on testosterone rather than DHT, form normally. That means organs like the vas deferens, seminal vesicles, and epididymis develop, but the external anatomy can range from underdeveloped male genitalia to an appearance that resembles female anatomy. Newborns may have what looks like unfused labia rather than a scrotum, and a phallus that resembles a clitoris more than a penis. The testicles often remain undescended, and the prostate is small or absent.
This condition, called 5-alpha reductase deficiency, is rare and genetic. The phenotype can vary widely from child to child, even within the same family.
What Changes at Puberty
One of the more striking aspects of congenital low DHT is what happens when puberty arrives. The surge of testosterone at puberty partially compensates for the missing DHT. The phallus can enlarge significantly, the testes may descend into the labioscrotal folds, the voice deepens, and facial hair begins to grow. These changes can be dramatic enough that children raised as female transition to a male identity, a phenomenon documented in several populations where the deficiency is more common.
However, puberty in these individuals still differs from typical male puberty. Facial hair growth tends to be reduced, and prostate development remains limited.
Low DHT in Adult Men
For adult men, low DHT most commonly occurs either because of low testosterone (hypogonadism) or because of medications that block the converting enzyme. The symptoms overlap with low testosterone but have some DHT-specific features.
Reduced body and facial hair growth is one of the more noticeable signs. DHT is the primary driver of hair growth in androgen-sensitive areas like the face, chest, and back. Men with low DHT may also notice changes in sexual function, though testosterone itself plays the larger role in libido and erectile function.
There’s also a connection between DHT levels and lean body mass. A large study of older men through the Cardiovascular Health Study found that both testosterone and DHT were positively associated with lean body mass, with each standard-deviation increase in DHT corresponding to about 0.17 kg/m² more lean mass. Interestingly, the same study found no significant link between DHT levels and bone mineral density at the hip or femoral neck, suggesting that DHT’s skeletal role may be less important than previously thought.
Mood and Depression
Low DHT may carry psychological effects. Research has found that DHT levels are inversely associated with depression scores, meaning lower DHT correlates with more depressive symptoms. A prospective study of men taking finasteride (a drug that blocks DHT production) found statistically significant increases in depression scores after treatment. The overall change was small but consistent. Animal studies support this connection: DHT has shown antidepressant-like effects in male rats, and replacing DHT in castrated rats partially reversed depression-like behavior.
Anxiety scores also trended upward in the finasteride study, though that increase didn’t reach statistical significance. The mechanism likely involves DHT’s role as a neurosteroid, meaning it has direct activity in the brain beyond its effects on reproductive tissues.
Medications That Lower DHT
The most common reason for low DHT in otherwise healthy men is medication. Two drugs are widely prescribed to block DHT production: one typically used for hair loss at lower doses, and another used for prostate enlargement. Both work by inhibiting the same enzyme that converts testosterone to DHT, but they differ in potency.
The stronger of the two reduces serum DHT by about 93% to 95%, while the other reduces it by roughly 70%. These are substantial reductions, and they explain why side effects can include changes in sexual function, mood, and body composition. For most men, these effects resolve after stopping the medication, but a subset report persistent symptoms.
If you’re taking one of these medications and noticing mood changes, reduced libido, or other new symptoms, that’s worth discussing with your prescriber. The DHT suppression is the intended mechanism of action, not a side effect, so the only way to reverse it is to adjust or stop the medication.
Low DHT in Women
Women produce much less DHT than men, and their bodies don’t rely on it for normal development or function. Studies of women born with a complete inability to produce DHT show essentially normal female growth and development. The only documented effects are minor: slightly reduced body hair and a mild decrease in pubic hair.
This means that for women, low DHT is generally not a clinical concern. Female physiology doesn’t depend on significant DHT activity, and even dramatic losses of the hormone produce only subtle changes.
How Low DHT Is Identified
Low DHT isn’t part of routine blood work. It’s typically measured when there’s a clinical reason, such as ambiguous genitalia in a newborn, delayed or atypical puberty, or symptoms that don’t match testosterone levels alone.
The key diagnostic marker for an enzyme deficiency is the ratio of testosterone to DHT. In normal males after stimulation testing, this ratio averages around 10.7, with a range of roughly 3.5 to 14. In men with the enzyme deficiency, the ratio jumps to 35 or higher, sometimes reaching into the 80s. That elevated ratio reflects testosterone building up because it isn’t being converted to DHT at a normal rate.
For adult men whose low DHT stems from low testosterone, the path forward involves addressing the underlying testosterone deficiency rather than targeting DHT specifically. DHT levels will rise naturally once testosterone production or supplementation normalizes.