How Do Anabolic Substances Work? - Episode 7: Aromatization, DHT and Androgen Metabolites

1. Testosterone is not the end of the road

In previous episodes we followed testosterone, the androgen receptor, and pharmacokinetics. The next step is essential: once testosterone reaches a tissue, the body can transform it. Different biological signals can then appear, with different effects.

The best-known transformations are conversion by aromatase into estradiol and conversion by 5-alpha-reductase into dihydrotestosterone, or DHT. But the map is larger: androgen precursors, intermediate metabolites, and inactivation pathways also exist. Androgen metabolism is essentially a local laboratory that can modify the hormonal message before the tissue responds.

2. What does aromatization mean?

Aromatization is the process by which the enzyme aromatase, also called CYP19A1, converts certain androgens into estrogens. In the case of testosterone, the main product is estradiol.

For a general reader, the key idea is this: testosterone can be transformed into a molecule with a different receptor target and different effects. A signal that starts as androgenic can therefore also generate an estrogenic signal.

3. Why is aromatase important in men too?

Estradiol is not an exclusively female hormone. In men, most circulating estradiol is generated through peripheral aromatization of testosterone, and this estrogen participates in bone, metabolic, and sexual physiology.

This is one of the most important corrections in hormone discussions: estrogen is not the opposite of male health. It is a normal component of male endocrinology. [Source: endocrinology literature on testosterone and estradiol]

4. Where is aromatase found?

Aromatase is expressed in several tissues, including adipose tissue, brain, bone, and gonads. Therefore, conversion of androgens to estrogens is not an event confined to one organ.

This distribution helps explain differences between people. Body composition, metabolic state, age, and tissue characteristics can influence local conversion.

5. What is DHT?

DHT, or dihydrotestosterone, is a testosterone metabolite formed through the action of 5-alpha-reductase enzymes. DHT is a potent androgen and binds the androgen receptor with higher affinity than testosterone.

Importantly, DHT is not simply “stronger testosterone everywhere.” Conversion occurs in particular tissues, and the effects depend on where the enzyme and receptor are present. [Source: NCBI Endotext and androgen receptor reviews]

6. 5-alpha-reductase: the enzyme that changes the signal

5-alpha-reductase converts testosterone into DHT. Different enzyme isoforms have different tissue distributions, and local enzyme activity contributes to tissue-specific androgen responses.

This is a key concept for the entire series: a tissue does not merely receive a hormone. It can process that hormone before the receptor sees the final signal.

7. DHT and the prostate

The prostate is one of the classic tissues in which conversion of testosterone to DHT has biological importance. DHT participates in prostate development and function and is relevant to understanding androgen pharmacology.

This does not mean that one isolated DHT result can describe prostate health. Clinical context, age, symptoms, and medical evaluation matter more than a single marker.

8. DHT and the skin

Skin and sebaceous glands respond to androgens. DHT is important in local processes that influence sebaceous-gland activity and characteristics of hair follicles.

This provides a visible example of androgen pharmacology: the same family of signals pursued for muscular effects can also contribute to sebum production and acne in skin.

9. DHT and the hair follicle

Hair follicles respond differently depending on the body region. Androgens can support terminal hair growth in some areas, while in the scalp, in genetically susceptible people, androgen signaling can contribute to follicular miniaturization.

This paradox again shows that there is no single body-wide response to androgens. Local responses depend on receptors, enzymes, and the biological program of each tissue.

10. Testosterone and estradiol are connected

Through aromatase, testosterone can become estradiol. Therefore, more testosterone available to tissues can alter flow through the estrogen pathway, depending on aromatase activity.

This relationship should not be reduced to the simple idea of “too much estrogen.” Estradiol has physiological roles, and interpretation depends on symptoms, context, and the laboratory method.

11. What happens if aromatase is inhibited?

Aromatase inhibition reduces conversion of androgens into estrogens. For this reason, medicines that affect aromatase have specific medical uses. But lowering estrogen is not automatically beneficial in every context.

In men, estradiol contributes to bone health and other functions. A healthy endocrine system is not simply trying to achieve the lowest possible estrogen.

12. Aromatization varies between people

Aromatase activity is influenced by tissue, genetics, body composition, and metabolic context. Two people with similar androgen exposure can therefore have different estradiol concentrations and different symptoms.

This is another pharmacological rule: the same exposure does not necessarily produce the same metabolite concentration or the same clinical effect.

13. Androgen metabolism does not stop at DHT

DHT can be further metabolized into products such as androstanediols, while testosterone and other precursors can enter multiple metabolic pathways. Some products are less active, while others can retain biological activity in particular tissues.

Intracrinology reviews show that androgen activation and inactivation can occur within target tissues and that metabolite profiles can reveal local production that is not obvious from circulating concentrations. [Source: PubMed, Intracrine androgen biosynthesis, metabolism and action revisited]

14. What are intracrine androgens?

Intracrinology describes situations in which a tissue locally produces, activates, or inactivates steroid hormones without the entire process being directly reflected by hormones measured in blood.

This is important for understanding DHT and androgen metabolites. A cell can receive a relatively weak precursor and locally transform it into a more active signal.

15. Why blood does not tell the whole story

Blood tests measure circulation, not every chemical reaction occurring in every tissue. A testosterone concentration can be normal while local androgen metabolism is different.

This is why modern pharmacology pays attention to tissue metabolism, receptors, and metabolites, not only the concentration of the parent hormone in plasma.

16. Estradiol is not a useless metabolite

Estradiol produced by aromatization is biologically active. In bone, for example, estrogens participate in regulating remodeling, and in other tissues they contribute to endocrine and metabolic functions.

So when testosterone, DHT, and estradiol are discussed, they should be seen as an interconnected signaling network rather than a hierarchy in which one is good and another is bad.

17. Active metabolites and inactivation metabolites

Metabolism can increase or reduce steroid activity. Some transformations produce active molecules, while others prepare the compound for conjugation and elimination.

In the liver, oxidation, reduction, and conjugation reactions transform many androgens. In peripheral tissues, transformations may activate a local precursor or inactivate a signal.

18. 11-oxygenated androgens: a less familiar area

Beyond testosterone and DHT, there are 11-oxygenated androgens such as 11-ketotestosterone and 11-ketodihydrotestosterone. These compounds can activate the androgen receptor and represent part of the human androgen landscape that has received increasing attention in modern literature.

The main lesson is conceptual: human androgen biology is richer than the classic testosterone-DHT list. Not every pathway has equal importance in every person or tissue, but the pathways exist.

19. Androgen metabolites can become biological markers

Because metabolism leaves chemical traces, metabolite analysis is useful in endocrinology, research, and anti-doping science. Sometimes a metabolite is easier to detect than the parent molecule or provides more information about a specific pathway.

In anti-doping, identifying characteristic metabolites is one of the foundations for detecting many androgenic substances.

20. Why can a steroid have a different profile from testosterone?

A synthetic molecule may be more or less susceptible to aromatization, 5-alpha-reduction, and other transformations. It may also have its own metabolites, be cleared more slowly or quickly, or interact differently with tissues.

This is why the label “steroid” is not enough to predict biological behavior. We need to know how enzymes process the molecule and which metabolites result.

21. Aromatizable versus non-aromatizable

Some androgens can be converted by aromatase into estrogens, while others cannot follow that pathway. DHT, for example, is not aromatized into estradiol.

This difference changes the network of effects. Two molecules that activate the androgen receptor can create different endocrine landscapes if one generates estrogenic metabolites and the other does not.

22. Non-aromatizable does not mean consequence-free

Not producing estrogen through aromatization does not mean an androgen has no systemic effects. A non-aromatizable androgen can still affect the androgen receptor, metabolism, lipids, liver, hematology, or endocrine feedback.

Therefore, classifying a compound as aromatizable or non-aromatizable describes one branch of pharmacology, not the entire safety profile.

23. DHT is not automatically “bad,” and testosterone is not automatically “good”

DHT has normal physiological roles, including sexual development and function of androgen-sensitive tissues. Testosterone is also essential, but its effects depend on tissue and local conversion.

In pharmacology, moral labels such as good and bad are less useful than questions about exposure, tissue, metabolite, and biological context.

24. How does this connect to Strongman?

A strength athlete is primarily interested in muscle mass and recovery, but the body does not isolate those effects. The same androgenic signal can influence erythropoiesis, skin, hair, prostate, nervous system, metabolism, and reproductive function.

That is why a performance-pharmacology article should follow not only the original molecule, but also the products into which it is transformed.

25. What should an athlete understand from a laboratory test?

Total testosterone, DHT, and estradiol are different windows into a complex system. None, by itself, completely describes tissue exposure or risk.

Good interpretation combines the result with symptoms, history, other laboratory findings, and physiological context. With exogenous exposure, context becomes even more important because concentrations can move outside the usual physiological range.

26. Why one number should not be the target

Trying to “optimize” only testosterone, only DHT, or only estradiol ignores that these molecules are connected. Changing one metabolite can alter other pathways, and a laboratory result is not equivalent to a diagnosis.

In endocrinology, trends, properly repeated tests, and clinical context are often more informative than a single value.

27. A simplified map of androgen metabolism

A useful picture is this: testosterone sits near the center. One branch passes through 5-alpha-reductase toward DHT. Another branch passes through aromatase toward estradiol. Other enzymes transform testosterone and DHT into metabolites that may be active, less active, or prepared for elimination.

This branching tree is closer to reality than the idea of one molecule circulating unchanged through the entire body.

28. Conclusion: the real story is transformation

Testosterone is a reference molecule, but the body does not leave it unchanged. Aromatase can convert it to estradiol. 5-alpha-reductase can convert it to DHT. Other pathways generate intermediate and inactivation metabolites, while tissues use their own enzymes to regulate the local signal.

That is the key to androgen pharmacology: there is not only the original molecule, but a network of transformations. For an athlete, the effect pursued in muscle is only one consequence of a molecule that circulates and is processed throughout the body.

Selected references

This episode draws on endocrinology and pharmacology reviews covering testosterone, aromatase, DHT, the androgen receptor, intracrinology, and androgen metabolites, including PubMed-indexed literature and Endotext/NCBI resources.