Low testosterone

Low testosterone comes on slowly, and the slide is easy to blame on work, age, or kids.

• Tired after a full night’s sleep, and flat by mid afternoon
• Less interest in sex, and fewer or weaker morning erections
• Weight settling around the midsection that diet and exercise no longer move
• Longer recovery after workouts, and strength that will not come back
• A shorter fuse, a lower mood, or an emotional flatness that is hard to describe
• Trouble concentrating and a sense that your edge has gone

Most of these overlap with poor sleep, stress, depression, and thyroid problems, which is why the blood test matters. The symptoms that track most tightly with testosterone are the sexual onesEuropean Male Ageing Study, 3,369 men aged 40 to 79. Low sexual desire, fewer morning erections, and erectile dysfunction had a clear dose-response relationship with testosterone. Fatigue, low mood, and reduced physical capacity were related as well, more weakly.Wu et al., NEJM 2010, meaning low desire, fewer morning erections, and erectile problems. If you have one of those alongside the fatigue or the mood change, testosterone is worth testing.

In women, the clearest sign is a loss of sexual desire that used to be there and now is not. Low energy, low mood, and difficulty holding onto muscle often come with it, especially after menopause or removal of the ovaries.

Common, and more common every decade. In a random sample of Boston men aged 30 to 79, 1 in 4 had a low level. Among men who see a doctor for anything, it is 39 percent of those over 45. Among healthy men, about 1 in 8 in their 50s and half in their 80s are below the line. Levels are also drifting down across generations. The average in American men aged 15 to 39 fell by a quarter between 1999 and 2016, a drop age does not explain.

• 1 in 4

  Men over 30 have a low level

• 39%

  Of men over 45 who see a doctor

• 1 in 8

  Of men with symptoms are treated

• −25%

  Young men’s average since 1999

Araujo 2007; Mulligan 2006; Hall 2008; Harman 2001; Lokeshwar 2021.

For women the numbers work differently, because no single blood level counts as low. Levels fall by about half between the 20s and mid 40s and then hold. Menopause does not lower them further, but removing the ovaries does, and the pill cuts the active fraction by more than half. About 1 in 8 women aged 45 to 64 has low sexual desire that causes distress, the condition testosterone is best proven to treat.

• Half

  Of a woman’s testosterone is gone by her mid 40s

• −61%

  Less free testosterone on the combined pill

• −25 to 50%

  Lower after both ovaries are removed

• 1 in 8

  Women 45 to 64 have low desire with distress

Testosterone production peaks in your 20s and falls about 1 percent a year after 30. That is too slow on its own to explain how someone feels at 45, and the men with the lowest levels almost always have something else pushing them down.

Weight is the biggest of those. Carrying extra weight roughly doubles the oddsOdds ratios for low testosterone in 2,162 men aged 45 and older were 2.38 for obesity, 2.09 for type 2 diabetes, and 1.84 for hypertension.Mulligan et al., 2006, and type 2 diabetes does much the same. Sleep apnea, opioids, steroid medications, heavy drinking and short sleep all suppress production. One week of five-hour nights lowers it by 10 to 15 percentHealthy young men restricted to five hours of sleep for one week had daytime testosterone 10 to 15 percent lower.Leproult and Van Cauter, JAMA 2011. Most of these are treatable, which is why we look for them before we prescribe. Less often the problem is the testes or the pituitary that signals them, and the first panel measures LH and FSH to tell those apart.

In women, the pill and ovary removal account for most of what we see. The pill raises the protein that binds testosterone, so a normal total can still leave very little free to actIn a meta-analysis of 42 studies covering 1,495 women, combined oral contraceptives raised SHBG roughly threefold and reduced free testosterone by about 61 percent.Zimmerman et al., Hum Reprod Update 2014. Removing the ovaries takes out a source that keeps producing after menopause.

Two large placebo-controlled trials in men, the Testosterone Trials and TRAVERSE, and a pooled analysis of 36 trials in women, show what changes. A separate review shows when.

Drawn from the Testosterone Trials (NEJM 2016), TRAVERSE and its substudies (NEJM 2023, 2024), Walther 2019 meta-analysis, Neto 2015 meta-analysis, Islam 2019 meta-analysis, Saad 2011.

Energy and mood come first, usually within the first month. Sex drive follows over two to three months. Muscle, fat, and bone take six months to a year, and depend on what you do in the gym and the kitchen while your levels are normal. Many patients also report sharper focus and easier weight control. The trials measured those less directly, so we do not promise them.

Testing. One blood panel, fasting, before 10 a.m., covering total and free testosterone, SHBG, LH, FSH, estradiol, a blood count, PSA if you are over 40, metabolic panel, lipids, HbA1c, and thyroid. We repeat it when the result is borderline or does not fit your symptoms.

Who qualifies. A level below about 300 ng/dL plus at least one symptom that tracks with testosterone. If something fixable is suppressing it, sleep apnea, opioids, uncontrolled diabetes, recent weight gain, we address that alongside or before treatment.

Our default. Testosterone cypionate, injected under the skin with a small needle two or three times a week, 40 to 70 mg at a time. Cream if you would rather not inject. Enclomiphene if you are younger, planning a family, or your level is only moderately low. Testosterone pauses sperm productionSperm production stops while testosterone is being given, and most men recover within a year of stopping. hCG 500 IU every other day alongside testosterone maintained sperm counts in every man studied.Hsieh et al., J Urol 2013 while you are on it. If you want to keep fertility and testicular size, hCG goes alongside it. If you are trying to conceive now, we start with enclomiphene or hCG instead.

All of them deliver or restore the same hormone. They differ in how steady your level stays, what they do to your own production, and what they cost.

What we do not use. Pellets, because they spike, then fade within a few monthsA 900 mg pellet implant peaks at about 1,020 ng/dL at two weeks, and 29 percent of men are below 300 ng/dL by four months. Extrusion and infection each occurred in 1 of 15 men. In women, pellet users averaged 194 ng/dL, several times the top of the female range, and 58 percent had side effects.J Sex Med 2017; Jiang et al., Menopause 2021 and cannot be adjusted once implanted. The traditional 200 mg injection every two weeks, because it spikes to several times normal on day twoA single 250 mg injection peaks at about 2,900 ng/dL on day two, three to five times the upper limit of normal, and falls below 300 ng/dL by day 21. Hematocrit above 50 percent occurred in 67 percent of men on this pattern of injections versus 13 percent on gels.Ichihara et al., 2020; Pastuszak et al., 2015 and drops below normal before the next shot. Men on it feel great one week and flat the next. Small frequent injections hold the level steady all week, with far less effect on the blood count.

Routine estrogen blockers, either. You need estrogen for bone, libido, and fat controlBlocking estradiol in men increased body fat and reduced sexual desire and erectile function. Estradiol regulates fat, bone, and libido in men, not only testosterone.Finkelstein et al., NEJM 2013, and blocking it by default causes the problems it is meant to prevent. We use one only when there is a specific reason.

Follow-up. Labs at 6 to 8 weeks, at 6 months, then every 6 to 12 months. If your red cell count climbsThe Endocrine Society advises holding testosterone if hematocrit exceeds 54 percent, then resuming at a lower dose.Endocrine Society 2018, we lower or spread out the dose. Blood pressure rises a few points on most formulations, so we track that too. At six months we check whether the thing you came in for has changed. If it has, we keep going. If it has not, with your level in range, we look for the real cause rather than raising the dose.

Who qualifies. A persistent loss of sexual desire that bothers you, after we have looked at the other usual causes. We also treat women whose main complaint is energy, mood, or muscle. Patients report those benefits often and the trials measure them poorly, so we set a six-month checkpoint and stop if you are not better.

Our default. Testosterone cream at about a tenth of a male dose, 3 to 5 mg a day, applied to the lower abdomen or thigh. That is the dose the trials usedFemale dosing in the trials was a 300 mcg/day patch or 5 mg/day of 1 percent cream, roughly one tenth of a male starting dose. That produced 0.85 more satisfying sexual events per month, with improvements in desire, arousal, and orgasm.Islam et al., 2019; British Menopause Society 2022. There is no FDA-approved testosterone product for women in the US, so it is compounded. We use pharmacies that test their product, and we confirm you are absorbing it with a blood level.

Two ways to give it, both at a fraction of a male dose.

Not pellets. Pellet users average several times the top of the female rangeAmong 384 women on pellets versus 155 on FDA-approved therapy, average testosterone was 194 ng/dL against 16. Side effects occurred in 58 versus 15 percent, including abnormal bleeding in 55 percent, weight gain in 34 percent, and hair changes in 14 percent. Twenty percent went on to hysterectomy.Jiang et al., Menopause 2021, and most get side effects.

Target and follow-up. Your level stays inside the range of a premenopausal woman, roughly 27 to 58 ng/dLISSWSH reference ranges run 45.5 to 57.5 ng/dL in the 20s, 27.6 to 39.8 in the 30s, and 27.0 to 38.6 in the 40s. Levels above the range may reduce desire.ISSWSH 2021. Above that, desire can fall and side effects begin. We recheck at 4 to 6 weeks, then every 6 months. At these doses the side effects are mild acne or hair growthIn a meta-analysis of postmenopausal trials, acne occurred in 7.0 percent versus 4.7 on placebo, and excess hair in 10.7 versus 6.6 percent. No voice change or hair loss at normal female doses.Elraiyah et al., JCEM 2014 in a few percent more women than placebo, and no voice change. The serious ones come from male-range levels, so we measure.

Weight, sleep, and alcohol move testosterone in both directions. Losing 10 percent of your body weight Losing 10 percent of your body weight raises it by roughly 80 ng/dLIn a meta-analysis of weight-loss studies in men, diet-induced weight loss raised total testosterone by about 83 ng/dL and bariatric surgery by about 250 ng/dL.Corona et al., Eur J Endocrinol 2013, which for some men is the difference between low and normal. Treating sleep apnea, drinking less, and lifting weights all help, and all get easier once your level is normal. That is why we do both.