Symptom
Lower sex drive
Fewer/weaker morning erections
Erectile dysfunction
Persistent fatigue/low energy
Loss of muscle/strength
Increased belly fat/weight gain
Low mood/irritability
“Brain fog”/poorer focus
Hot flushes/sweats
Smaller testes/fertility issues
Gynaecomastia (breast tissue)
Reduced bone density (longer term)
Approx. prevalence in men with low T*
50–70%
40–70%
40–60% (more likely when T is very low)
50–65%
40–60%
40–60%
20–40%
20–40%
5–20% (typically with more severe deficiency)
10–30% (varies with LH/FSH changes)
5–10%
10–30%
Features
How it works
What studies show
Speed
Hormones in blood
Side effects
Topical dutasteride
Applied directly to thinning areas on the scalp. Works mainly where you put it, with less effect on the rest of the body.
In studies, the 0.05% strength gave thicker, denser hair in 24 weeks and even outperformed oral finasteride.
Hair grows in slow cycles, so results take time.
Blood tests show only small changes in hormones, which may mean a lower risk of whole-body side effects.
Side effects are usually mild and limited to the scalp (such as irritation or dryness).
Oral dutasteride
Taken as a capsule by mouth. Circulates throughout the body, lowering DHT everywhere.
Has shown strong regrowth in several trials and, at higher doses, can outperform finasteride.
Results also build gradually, though some people feel they notice changes sooner.
Causes bigger drops in DHT and slight hormone shifts, which can raise the chance of whole-body side effects.
Side effects are more often reported than with topical use, including sexual side effects and mood changes (in a minority of men).
