Andropause Is Real, and Genetics Explain Why It Hits Some Men Harder

A lot of men who bring up low energy, reduced motivation, or a noticeable drop in libido to their doctor get a version of the same response: your bloodwork looks normal, this is probably just part of getting older. Sometimes that’s an accurate and reasonable answer. Sometimes it’s a frustrating dead end for a man whose experience genuinely doesn’t match what “normal aging” is supposed to feel like.

Andropause, the gradual, age-related decline in testosterone and related hormonal shifts in men, is real, well documented, and genuinely underdiscussed compared to its female counterpart. It’s also far from uniform. Some men move through their 40s, 50s, and beyond with only mild hormonal changes. Others experience a much more noticeable shift, sometimes despite bloodwork that technically falls within a normal range. Genetics is a significant part of why these experiences diverge so much.

This isn’t about assuming every man over 40 needs hormone therapy or treating fatigue as automatically hormonal. It’s about taking seriously that andropause, like most biological processes, doesn’t happen the same way in every body, and that genetics offers real insight into why.

Andropause Isn’t Like Menopause, and That Confuses the Conversation

Part of why andropause gets dismissed so often is that it doesn’t look like menopause. There’s no clear endpoint, no single defining moment like the last menstrual period. Testosterone typically begins a slow, gradual decline starting sometime in a man’s 30s, continuing at a modest pace for decades rather than dropping sharply within a few years. Because the change is so gradual, it’s easy for both doctors and patients to attribute symptoms to almost anything else, stress, poor sleep, general aging, before hormonal changes get seriously considered. Genetics is part of what determines whether that gradual decline stays genuinely mild or becomes significant enough to produce real symptoms.

Why Some Men Notice Symptoms Sooner Than Others

Two men in their late 40s can have testosterone levels that look nearly identical on paper and report completely different experiences. Genetics is a major reason why.

The Pace of Testosterone Decline

While average testosterone decline follows a fairly predictable downward trend with age at the population level, the actual rate varies meaningfully between individuals. Genetic variants involved in testosterone production within the testes can influence how quickly this decline proceeds for a given person, meaning some men experience a much steeper drop over the same number of years than others with otherwise similar health profiles.

Genetic Factors in Testosterone Production

Multiple genes are involved in the pathway that produces and regulates testosterone, and variants across this pathway can affect baseline production, how efficiently the body responds to the signals that trigger testosterone synthesis, and how that production changes with age. This is part of why lifestyle factors like sleep, exercise, and body composition, while genuinely important, don’t fully explain why some men maintain more stable hormone levels than others facing similar circumstances.

The SHBG Problem: Why “Normal” Bloodwork Doesn’t Tell the Whole Story

One of the more overlooked pieces of this picture is a protein called sex hormone-binding globulin, or SHBG, which binds to testosterone in the bloodstream and makes it unavailable for use by tissues. Genetic variants that increase SHBG production mean that a meaningful portion of a man’s testosterone can be bound up and effectively inactive, even when total testosterone on a standard blood test looks entirely normal.

This matters because most routine testosterone tests measure total testosterone rather than free, unbound testosterone, the portion actually available for the body to use. A man with elevated SHBG due to genetic factors can have symptoms consistent with low testosterone while his total testosterone reading reassures his doctor that everything is fine. This is one of the more common reasons men feel dismissed after bloodwork that technically falls within range.

Androgen Receptor Sensitivity: The Overlooked Variable

Even when testosterone is available and unbound, how effectively the body responds to it depends on androgen receptor sensitivity, which is influenced by genetic variation, including in a gene called AR. Some men have receptors that respond strongly to a given amount of testosterone, while others have receptors that are comparatively less responsive, requiring more circulating testosterone to produce the same physiological effect. This helps explain why two men with identical free testosterone levels can experience meaningfully different symptoms; the hormone is present in both cases, but the body’s ability to actually use it differs.

Estrogen Conversion and Why It Matters for Men Too

Testosterone doesn’t stay testosterone forever. An enzyme called aromatase converts a portion of it into estrogen, a normal and necessary process in men as well as women, but one that varies in efficiency from person to person based on genetics. Men with variants that increase aromatase activity convert more testosterone into estrogen than average, which can leave less testosterone available for its primary functions while also shifting estrogen levels higher than typical for men. This dual effect, lower effective testosterone alongside relatively higher estrogen, can contribute to symptoms that don’t always get connected back to this particular genetic factor.

Taking the Symptoms Seriously, Without Overcorrecting

None of this is meant to suggest every man experiencing fatigue or low mood has an undiagnosed hormonal issue, or that hormone therapy is the answer for everyone who notices these changes. It’s meant to push back on the idea that “your bloodwork looks fine” is always the end of the conversation. Between decline pace, SHBG binding, receptor sensitivity, and estrogen conversion, there are several genetically influenced variables that standard total testosterone testing simply doesn’t capture.

Understanding your own genetic tendencies in these areas doesn’t replace a conversation with your doctor. It gives you a more informed starting point for that conversation, and a better sense of which additional questions or tests might actually be worth asking about.

Frequently Asked Questions

Is andropause a medically recognized condition?

The gradual, age-related decline in testosterone is well documented and recognized in medical literature, though it’s less standardized as a diagnosis than menopause and tends to receive less clinical attention. Symptoms and severity vary widely between individuals.

Why would my testosterone bloodwork look normal if I have symptoms?

Standard testing typically measures total testosterone, which includes hormone that’s bound to proteins like SHBG and unavailable for the body to use. Genetic variants that increase SHBG production can leave a man with normal total testosterone but lower effective, usable testosterone, which routine testing often misses.

Does genetics really affect how sensitive my body is to testosterone?

Yes. Variants in the androgen receptor gene influence how strongly the body responds to a given amount of testosterone. This means two men with identical free testosterone levels can experience different symptoms depending on how sensitive their receptors are.

Can testosterone really convert into estrogen in men?

Yes, through an enzyme called aromatase, and this is a normal process. However, genetic variants that increase aromatase activity can shift the balance further than average, converting more testosterone into estrogen and potentially contributing to symptoms related to lower effective testosterone.

Should I ask my doctor for hormone therapy if I think I have andropause?

That’s a decision to make with your doctor based on a full evaluation, not something to pursue based on genetic information alone. Genetic insight can help inform a more specific conversation about testing, including free testosterone and SHBG levels, but treatment decisions should always involve a healthcare provider.