What Causes Low Sex Drive in Men?
By Dr. Leonard W. Liang, MD | Urology | Downtown Los Angeles
Have you noticed your interest in sex fading but assumed it was just part of getting older? Most men do. And most men are at least partly wrong. While testosterone does decline naturally with age, a noticeable or persistent drop in sex drive is not something to simply accept without finding out why. Low libido in men has real, identifiable causes ranging from hormonal imbalances to medications to underlying health conditions. Knowing what is behind it is the first step toward doing something about it.
It Is Not the Same as Erectile Dysfunction
This is worth clarifying upfront because men often confuse the two. Low libido and erectile dysfunction are different problems. A man can have no trouble achieving an erection but feel little to no desire to initiate sex. Another man might have strong desire but difficulty with physical function. Sometimes both exist at the same time, but they come from different places and respond to different treatments.
Understanding which one you are dealing with, or whether both are in play, is one of the first things a urological evaluation sorts out.
Testosterone Is the Most Obvious Culprit, But Not Always the Answer
When a man loses interest in sex, low testosterone is usually the first thing that comes to mind. For good reason. It is the most direct hormonal driver of libido in men, and it is measurable. The AUA defines low testosterone as a level below 300 ng/dL, confirmed on two separate morning blood tests.
The important caveat is this: testosterone replacement therapy improves libido in men with confirmed low testosterone. It does not improve libido in men with normal levels. Testing before treating is not optional. It is the whole point.
Low testosterone also rarely shows up alone. Fatigue that does not improve with rest, difficulty concentrating, noticeable loss of muscle mass, increased body fat, and a low mood alongside reduced sexual interest are all part of the picture. When several of these are present together, a hormonal workup is the right next step.
Depression and Anxiety Do More Damage Here Than Most Men Realize
This is the one that gets missed most often. Not because it is rare, but because men are less likely to connect emotional health to sexual health. Depression blunts the pleasure response across the board. It does not selectively spare libido. Chronic anxiety keeps the nervous system in a state of low-level alert that is physiologically at odds with sexual desire.
What makes this harder to untangle is that it runs in both directions. Low sex drive contributes to depression and relationship stress. Those things then suppress libido further. By the time a man comes in, sometimes it has been going on long enough that both sides of the cycle are well established.
Addressing the psychological piece directly, whether through therapy, medication review, or both, is not secondary to treating the physical side. For many men it is the primary intervention.
The Medication Nobody Mentions
A lot of men on antidepressants notice a significant drop in sexual desire and never connect the two. SSRIs and SNRIs, the most commonly prescribed antidepressants, list reduced libido as one of their most consistent side effects. So do beta-blockers, certain blood pressure medications, corticosteroids, opioids, and anabolic steroids.
This does not mean stopping a medication without talking to a doctor. It means the medication list is always part of the conversation in a proper evaluation. Sometimes a simple timing adjustment helps. Sometimes switching to a different medication in the same class resolves it. Either way, it is a conversation worth having rather than assuming nothing can be done.
Prolactin, Thyroid, and the Hormones Most People Never Check
Testosterone gets most of the attention, but it is not the only hormone that affects libido. Elevated prolactin, a condition called hyperprolactinemia, suppresses testosterone production and directly reduces sexual desire. Thyroid dysfunction, both overactive and underactive, affects energy, mood, and hormonal balance in ways that show up as reduced libido before anything else.
The 2024 International Consultation on Sexual Medicine specifically notes that low libido in men can stem from elevated prolactin, thyroid imbalance, and other hormonal factors beyond testosterone alone. A workup that only checks testosterone is an incomplete workup. It is one number in a larger picture.
Chronic Illness, Lifestyle, and the Slow Accumulation
Obesity, type 2 diabetes, cardiovascular disease, and obstructive sleep apnea all suppress testosterone and sexual desire through multiple overlapping pathways. Sleep apnea in particular is underrecognized in this context. Disrupted sleep reduces testosterone production, increases cortisol, and depletes the energy needed to maintain any kind of sexual interest. Men with untreated sleep apnea who are also dealing with low libido sometimes find that treating the apnea moves the needle more than anything else.
Alcohol is worth mentioning separately. The CDC defines heavy drinking as more than two drinks per day for men, and chronic heavy use suppresses testosterone production and affects the neurological pathways that regulate sexual desire in ways that do not simply resolve when the drinking stops.
Relationship and Life Context
Libido is not purely biochemical. Relationship dissatisfaction, unresolved conflict, poor communication around intimacy, grief, major life stress, and burnout all suppress sexual desire in ways that are entirely real even when the bloodwork looks normal. The MSD Manual identifies relationship problems as one of the most common psychological contributors to low libido in men.
This does not make it less worth addressing. It makes it worth addressing differently. Ignoring the relational or psychological context and treating only the hormones rarely produces lasting improvement.
Why Getting Evaluated Matters
Low libido is often a symptom before it is a condition. Low testosterone is a documented risk factor for cardiovascular disease. Depression worsens when left unaddressed. Sleep apnea carries serious long-term health consequences. A man who writes off a gradual drop in sex drive as aging may be missing an early signal that is far easier to act on now than it will be in two or three years.
A proper evaluation covers medical and sexual history, a full medication review, morning testosterone along with prolactin and thyroid function, metabolic markers, and a physical exam where relevant. The picture that emerges from that is usually clear enough to know exactly where to start.
What Talking to Dr. Liang Looks Like
At Dr. Liang’s practice, low libido is evaluated as part of a broader look at men’s urological and sexual health. The goal is finding what is actually driving the change and addressing that specifically, not offering a standard solution before understanding the individual situation.
If low testosterone is confirmed, treatment options are explained clearly and without pressure. If other contributors come up, those are addressed as part of the same conversation rather than handed off elsewhere.
Dr. Liang’s office is located at 1513 S Grand Ave, Suite 300, Downtown Los Angeles, CA 90015. Office hours are Monday through Friday, 9 AM to 5 PM. The office can be reached at (213) 749-0662, or an appointment can be booked at leonardliang.com/contact-us.
Related pages on this site:
ViaSure for Erectile Dysfunction | About Dr. Liang | Contact & Appointments
