DHT (dihydrotestosterone): what the result means, and what lowering it costs

Almost every page about DHT treats it as a number to get rid of. The more useful questions are what a serum DHT result can actually tell you — which is less than you would hope — and what you give up if you decide to suppress it.

DHT is not a stronger testosterone. It is a different compartment.

Dihydrotestosterone is testosterone with a single double bond reduced away. The enzyme that does it, 5-alpha-reductase, comes in two main isoforms with different homes: type 1 in skin, sebaceous glands and liver, type 2 in the prostate, genital skin and the hair follicle. The reaction runs one way. DHT cannot be converted back to testosterone, and it is not a substrate for aromatase, so unlike testosterone it never becomes estradiol.

Established clinical use At the androgen receptor DHT is the stronger ligand. In classical binding work on the human androgen receptor, DHT bound with roughly twice the affinity of testosterone, and testosterone came off the receptor about five times faster ¹. That is where the folk version comes from — DHT is the real androgen, testosterone is just the precursor. The same experiments undercut it: at high enough concentrations, testosterone occupied and activated the receptor much as DHT did ¹. Greater potency is not exclusivity.

Established clinical use The second point is the one most pages skip. Blood is not where DHT does its work. Circulating DHT sits at roughly a tenth of circulating testosterone, because most DHT is made inside target tissue from testosterone that arrived there, used locally, and only then leaked out — and intracellular androgen concentrations in androgen-sensitive tissue are substantially independent of circulating concentrations ². A serum DHT is a spillover reading from a process happening somewhere you are not sampling. It is a real measurement. It is a weak proxy for what your scalp or prostate is seeing.

Three units and an assay that changes the answer

DHT is reported in at least three units, and the spread between them is wide enough to cause real errors. The canonical unit here is ng/dL. A pg/mL figure is ten times the ng/dL figure, so 450 pg/mL and 45 ng/dL are the same blood. A nmol/L figure is the ng/dL figure divided by 29.04, so a generic 30–85 ng/dL band is 300–850 pg/mL, or 1.03–2.93 nmol/L. The predictable failure is seeing 450 on a report written in pg/mL, comparing it against a range written in ng/dL, and concluding you are five times over the top when you are sitting mid-band. Check the unit before you interpret the number, and use the interval your own laboratory printed rather than any generic band, including the one on this page.

Established clinical use Method matters more for DHT than for almost any other androgen, for the same reason it matters for estradiol in men: the analyte sits near the bottom of what an immunoassay resolves, and the compound it most resembles chemically is present at ten times the concentration. When a validated LC-MS/MS method was compared with established immunoassay methods, serum DHT read consistently lower by mass spectrometry, and chromatographic clean-up before the immunoassay narrowed the gap — the signature of interfering substances rather than of genuinely higher DHT ³. The same work found even the collection tube could shift results, with fluoride tubes giving DHT around 15% lower than plain tubes ³. The parallel argument for estradiol is laid out here.

The practical consequence is dull and important. Record the method beside every DHT you log. An immunoassay DHT and an LC-MS/MS DHT drawn a month apart are not two points on a trend; they are two different measurements sharing a name. If a DHT looks high and the report does not say how it was produced, the first question is not what to do about the level.

Why DHT climbs on testosterone therapy, and why gels climb hardest

Established clinical use DHT rises when testosterone rises, roughly in proportion, because testosterone is the substrate. Less widely known is that the route changes the ratio and not only the level. A steady-state comparison of a transdermal testosterone patch against a transdermal gel in hypogonadal men found DHT concentrations and DHT/testosterone ratios two- to three-fold higher on the gel ⁴. Manufacturer labelling for a testosterone gel reports DHT rising in parallel with testosterone throughout treatment, with steady-state DHT/testosterone ratios of roughly 0.23 to 0.33 depending on how much was applied ⁵.

The mechanism is not mysterious. Skin is rich in 5-alpha-reductase and a gel is spread across a large area of it, so a meaningful fraction of the dose is reduced on the way in. An injection largely bypasses that. This is worth knowing before you reach for a pathological explanation: a raised DHT and a raised DHT/testosterone ratio on a transdermal preparation is the expected pharmacology of that route. The same absolute number would mean something different on an injectable.

Established clinical use Whether the elevation causes harm is a separate question, and the honest answer is that the evidence is thinner than either camp claims. The most thorough review of the subject concluded that available data are limited by the absence of large, long, well-controlled trials, and that on balance modest elevations of circulating DHT during testosterone replacement do not appear to have adverse effects ². That is a cautious conclusion, not a clean bill of health. It sits alongside practice: the Endocrine Society guideline builds monitoring around symptoms, serum testosterone, haematocrit and prostate assessment, and does not make DHT a routine monitoring target ⁶. If a high DHT on a gel is bothering you, the lever that moves it is the route, and route is a prescription decision — take the result, with its method and its units, to the clinician who prescribes for you.

Hair loss is a sensitivity, not a level

Established clinical use Hair is the most common reason people order a DHT, and it is the question the test is least able to answer. When serum DHT was measured in people with androgenetic alopecia and compared with controls, mean DHT did not differ significantly between the groups, and higher DHT did not track with more advanced alopecia; raised concentrations turned up in the control group as well ⁷. The authors' own conclusion was that the decisive variable is the genetically determined sensitivity of the follicle, not the amount of DHT available to it ⁷.

Animal-only or theoretical That fits the compartment argument above. Balding and non-balding scalp differ in local 5-alpha-reductase activity and androgen receptor density, so the exposure that matters is generated and read inside the follicle, largely uncoupled from what is circulating ². This is mechanism and extrapolation rather than a demonstrated causal chain in individual people, and it should be held loosely — but it explains the observation cleanly. Two men with identical serum DHT can have entirely different scalps.

So here is what a DHT result cannot do. It cannot tell you whether you will lose hair. It cannot tell you that you have too much DHT for your follicles, because there is no threshold to compare against. A DHT inside 30–85 ng/dL does not protect you, and one above 85 ng/dL is not a diagnosis. Being outside a generic band is not a finding. If your hair is receding, the informative examination is of your scalp and your family history, not of your serum.

What suppression actually costs

Established clinical use 5-alpha-reductase inhibitors work, in the narrow sense that they do what they promise to the number. In a year-long randomised placebo-controlled trial, dutasteride suppressed serum DHT by about 94% and finasteride by about 73% at the doses studied, while serum testosterone rose transiently ⁸. Dutasteride inhibits both isoforms; finasteride is selective for type 2, which is why one suppresses more deeply than the other. If your only objective is a lower DHT on a report, these drugs deliver it comprehensively.

Off-label or community practice Adding a 5-alpha-reductase inhibitor to testosterone therapy specifically to blunt the DHT rise is common in this community and among some clinicians who prescribe testosterone, but it is not an approved indication — the licensed indications are male pattern hair loss and benign prostatic hyperplasia. What the trial evidence says about the cost is genuinely mixed. A meta-analysis of randomised controlled trials found these drugs associated with increased sexual dysfunction overall, with pooled relative risks above one for erectile dysfunction and for reduced libido in men treated for prostate enlargement, while the same association in the hair-loss trials was smaller and did not reach statistical significance ⁹.

That inconsistency deserves stating rather than smoothing. A review of the same drug class from a urological perspective reached close to the opposite conclusion: that 5-alpha-reductase inhibitors do not cause erectile dysfunction to a clinically significant degree, and that DHT is less relevant than testosterone to erectile function in the first place ¹⁰. Both readings are defensible from the published data. What they share is that the effect, where it exists, is a minority effect. The community claim that these drugs reliably destroy libido is not supported by the trials. Neither is the counter-claim that the risk is zero.

Established clinical use The persistence question is where the argument gets hot, and where the regulatory record is clearer than the science. United States labelling for the finasteride product licensed for hair loss lists sexual adverse reactions — erectile dysfunction, libido disorders, ejaculation and orgasm disorders — reported to have continued after the drug was stopped, and lists depression and suicidal ideation among reported adverse reactions ¹¹. The European Medicines Agency completed a formal review of finasteride- and dutasteride-containing products and required measures to minimise the risk of suicidal thoughts ¹². None of that establishes causation; adding a reported adverse reaction to a label is not a finding of cause. Whether post-finasteride syndrome is a distinct clinical entity, how often it occurs, whether it persists and by what mechanism all remain disputed in the peer-reviewed literature ¹³.

The shape of the decision is therefore this: a drug that reliably removes most of your circulating DHT, in exchange for a modest and contested increase in sexual and mood adverse effects, plus a rare, unresolved and severe tail the literature has not settled. That is a real trade with real numbers on both sides — not a free win, and not a catastrophe. It is also not a trade to make from a lab result, because the lab result cannot tell you how likely you are to lose hair in the first place. Take the question, the DHT value, its assay method and your actual scalp to the clinician who would write the prescription, monitor it and stop it. That is the person who has to hold both halves of the trade.

What the app records for this marker

How the app adjusts this range by sex and age

Generated by running the app's own range function against each band, so this table cannot drift from what the app flags against. The optimal column is non-diagnostic throughout.

Compounds whose monitoring panel includes this marker

Generated by matching this marker's own aliases against the monitoring note on every compound in the app's reference, so the list is the app's, not an author's.

• Dutasteride / Finasteride Total T, Free T, DHT levels (if testing available), PSA, sexual function self-assessment monthly.
• Proviron Free Testosterone; SHBG; Estradiol (E2); Lipid panel; DHT

Questions people actually ask

What is a normal DHT level?

A commonly quoted adult male range is 30 to 85 ng/dL, which is 300 to 850 pg/mL or 1.03 to 2.93 nmol/L. Published ranges vary widely between laboratories — some report 11 to 95 ng/dL — because they depend on the assay and the reference population used to set them.

Use the interval printed on your own report. It is the only range matched to the method that produced your number. A generic band, including the one quoted here, is a fallback for when your report does not give one.

My DHT is high on a testosterone gel. Is that a problem?

A raised DHT and a raised DHT-to-testosterone ratio on a transdermal preparation is the expected pharmacology of that route rather than a sign that something has gone wrong. Skin is rich in 5-alpha-reductase and a gel is applied across a large area of it, so a meaningful share of the dose is converted on the way in. Patch-versus-gel comparisons found gel DHT and DHT/testosterone ratios two- to three-fold higher.

The best available review concluded that modest elevations of circulating DHT during testosterone replacement do not appear to cause harm, while noting that large, long, well-controlled trials do not exist. If the number bothers you, the variable that actually moves it is the route of administration, and that is a conversation with your prescribing clinician.

Does a high DHT mean I am going to lose my hair?

No. Serum DHT does not separate people with androgenetic alopecia from people without it, and it does not track with how advanced the hair loss is. Raised serum DHT appears in people with full heads of hair.

Hair loss is driven by the genetically determined sensitivity of the follicle and by local androgen metabolism inside the scalp, which is largely uncoupled from what is circulating. That is why a DHT result cannot predict who loses hair, and why a result inside the reference range is not protective.

Will finasteride or dutasteride ruin my libido?

The evidence points in both directions and it is worth knowing that honestly. A meta-analysis of randomised trials found an increased relative risk of erectile dysfunction and reduced libido in men treated for prostate enlargement, with a weaker, non-significant signal in the hair-loss trials. A urological review of the same class concluded the drugs do not cause erectile dysfunction to a clinically significant degree.

Where an effect exists it is a minority effect, and most people who take these drugs do not report sexual dysfunction. Regulators in the United States and Europe have added persistent sexual adverse reactions and psychiatric warnings to the labelling, but causality and persistence remain disputed. This is a genuine trade-off to work through with the clinician who would prescribe and monitor it.

Should I ask for an LC-MS/MS DHT rather than an immunoassay?

Method matters more for DHT than for most androgens, for the same reason it matters for estradiol in men. DHT circulates at roughly a tenth of testosterone, near the bottom of what immunoassays resolve, and testosterone is chemically similar enough to interfere. Immunoassay reads DHT higher than mass spectrometry, and the gap closes when interfering substances are removed by chromatography.

The practical rule is to record the method alongside every result. An immunoassay DHT and an LC-MS/MS DHT are not two points on the same trend line, and comparing them will manufacture a change that never happened.

How do I convert DHT between pg/mL, ng/dL and nmol/L?

Multiply pg/mL by 0.1 to get ng/dL. Multiply nmol/L by 29.04 to get ng/dL. So 450 pg/mL is 45 ng/dL, and 2.0 nmol/L is about 58 ng/dL.

The pg/mL and ng/dL confusion is the one that causes real alarm, because a pg/mL number looks ten times larger than the range it is being compared against. Check the unit printed on the report before drawing any conclusion from the value.

Sources

Every claim above that is not a definition is either labelled by evidence tier or carries a numbered reference to one of these.

1. Grino PB, Griffin JE, Wilson JD. Testosterone at high concentrations interacts with the human androgen receptor similarly to dihydrotestosterone. Endocrinology 1990;126(2):1165-1172. Direct binding data: DHT binds the human androgen receptor with about twice the affinity of testosterone and testosterone dissociates roughly five times faster, but testosterone at high concentration behaves much like DHT at the receptor.
2. Swerdloff RS, Dudley RE, Page ST, Wang C, Salameh WA. Dihydrotestosterone: Biochemistry, Physiology, and Clinical Implications of Elevated Blood Levels. Endocrine Reviews 2017;38(3):220-254. The most complete review of what raised circulating DHT means; establishes that DHT runs at roughly a tenth of testosterone, that intracellular androgen concentrations are largely independent of circulating levels, and that modest elevations during testosterone replacement do not appear to have adverse effects on the available (limited) evidence.
3. Wang C, Shiraishi S, Leung A, Baravarian S, Hull L, Goh V, Lee PWN, Swerdloff RS. Validation of a testosterone and dihydrotestosterone liquid chromatography tandem mass spectrometry assay: interference and comparison with established methods. Steroids 2008;73(13):1345-1352. Establishes that immunoassay reads DHT higher than LC-MS/MS because of interfering substances, and that collection tube chemistry alters measured testosterone and DHT.
4. Comparison of the Steady-State Pharmacokinetics, Metabolism, and Variability of a Transdermal Testosterone Patch Versus a Transdermal Testosterone Gel in Hypogonadal Men. The Journal of Sexual Medicine. Head-to-head route comparison finding DHT concentrations and DHT/testosterone ratios two- to three-fold higher on the gel than on the patch.
5. AndroGel (testosterone gel) US prescribing information, US Food and Drug Administration. Regulatory labelling showing DHT rising in parallel with testosterone during transdermal gel treatment, with steady-state DHT/testosterone ratios of roughly 0.23 to 0.33.
6. Bhasin S, Brito JP, Cunningham GR, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2018;103(5):1715-1744. The guideline framework for monitoring testosterone therapy: symptoms, serum testosterone, haematocrit and prostate assessment, with DHT not a routine monitoring target.
7. Urysiak-Czubatka E, Kmieć ML, Broniarczyk-Dyła G. Assessment of the usefulness of dihydrotestosterone in the diagnostics of patients with androgenetic alopecia. Postepy Dermatol Alergol 2014;31(4):207-215. Found no significant difference in mean serum DHT between people with androgenetic alopecia and controls, and no correlation between serum DHT and severity of hair loss.
8. Clark RV, Hermann DJ, Cunningham GR, Wilson TH, Morrill BB, Hobbs S. Marked suppression of dihydrotestosterone in men with benign prostatic hyperplasia by dutasteride, a dual 5α-reductase inhibitor. J Clin Endocrinol Metab 2004;89(5):2179-2184. Randomised placebo-controlled comparison quantifying serum DHT suppression at one year: approximately 94% with dutasteride and 73% with finasteride.
9. Liu L, Zhao S, Li F, et al. Effect of 5α-Reductase Inhibitors on Sexual Function: A Meta-Analysis and Systematic Review of Randomized Controlled Trials. J Sex Med 2016;13(9):1297-1310. Pooled randomised trial data showing increased relative risk of sexual dysfunction, erectile dysfunction and reduced libido in benign prostatic hyperplasia populations, with a weaker and non-significant association in androgenetic alopecia trials.
10. Canguven O, Burnett AL. The effect of 5α-reductase inhibitors on erectile function. J Androl 2008;29(5):514-523. A review reaching the opposing conclusion — that 5-alpha-reductase inhibitors do not cause erectile dysfunction to a significant degree, and that DHT is less relevant than testosterone to erectile function.
11. PROPECIA (finasteride) tablets, US prescribing information, US Food and Drug Administration, 2022. Current US labelling listing sexual adverse reactions reported to continue after discontinuation, and depression and suicidal ideation among reported adverse reactions.
12. European Medicines Agency. Finasteride- and dutasteride-containing medicinal products: Article 31 referral — measures to minimise the risk of suicidal thoughts. The European regulator's formal review outcome requiring risk-minimisation measures for suicidal thoughts with 5-alpha-reductase inhibitors.
13. Cilio S, et al. Post-finasteride syndrome — a true clinical entity? International Journal of Impotence Research, 2025. Recent peer-reviewed review showing that the existence, frequency, persistence and mechanism of post-finasteride syndrome remain actively disputed.