The Ultimate Men’s Health Guide: Testosterone, Sex Drive, & Aging

KEYPOINTS

• 01

  Normal testosterone covers a wide range and declines about 1% a year

  Stanford urologist Dr. Michael Eisenberg, who leads Stanford's Male Reproductive Medicine and Surgery Program, puts normal at roughly 300–900 ng/dL. Levels peak between 20 and 30, then fall about 1% a year. Weight and metabolic health also pull them down. Below about 300, the share of men with low testosterone is roughly 10–20% in their 40s and 50s, 20% in their 60s, 30% in their 70s and 50% in their 80s. That is why 'half of men over 50' is the figure people quote.

• 02

  Low-T symptoms are vague, so test rather than guess

  The signs are low energy, low sex drive, poor mood, poor sleep, poor concentration and erectile problems. Clinical red flags include anemia, low bone mineral density and a history of chemotherapy. Eisenberg admits these are non-specific, but if they bother you or your partner notices them, get a simple blood test, ideally before 9–10 a.m. and fasted. One low result gets repeated before treatment is discussed. He suggests adding it to routine checks from around 40–50, or earlier with risk factors.

• 03

  Depression and low testosterone feed each other

  Low testosterone can impair mood, and depression can blunt the hormonal signalling that drives testosterone production. Mel says her husband, Chris, openly struggled with depression about five years ago: low energy, shut down and low sex drive. Those general changes can point to something deeper.

• 04

  Sleep, weight and anything heart-healthy raise testosterone

  Chronic short sleep (4–5 hours instead of 7–9), shift work and sleep apnea all suppress testosterone, and apnea and low T reinforce each other. Losing weight through a good diet and exercise, not starvation, improves levels. GLP-1 drugs and bariatric surgery reliably raise them. His rule: 'Anything that's good for your heart is good for testosterone.'

• 05

  Treatment comes in several forms, each with trade-offs

  Injectable testosterone is oil-based and usually given into the muscle every two weeks, in the thigh or, with a partner's help, the buttocks. Some men feel the peaks and valleys, so doses are sometimes given once or twice a week. Longer-acting injections last months. Daily gels avoid needles, and pellets go under the skin of the hip. Mel notes that some experts on her women's-hormone episodes distrusted pellets, and Eisenberg says the right form depends on preference.

• 06

  Taking testosterone suppresses sperm production

  Testosterone inside the testicle runs at around 5,000 or more, many times the blood level, and that high concentration is what drives sperm production. Testosterone from outside the body switches off the brain's signal, so internal levels drop and sperm counts fall. Other side effects include oily skin, acne, hair loss, breast growth (from conversion to estrogen) and higher red blood cell counts with clotting risk.

• 07

  The TRAVERSE trial eased heart and prostate fears

  In this landmark trial, about 5,000 men were given testosterone or a placebo gel and followed over time. It found no increase in prostate cancer or in heart attacks and strokes, and Eisenberg says the FDA is moving to update warning labels. He compares it to the way fears around female hormone therapy are being revised.

• 08

  If your levels are normal, don't take it

  Eisenberg warns about clinics that profit from prescribing and upselling to men with normal levels, exposing them to every side effect for no benefit. Men without working testicles need testosterone for life. Everyone else should treat it as a trial of about six months, adjusting form and dose to reach a therapeutic range. Men who see a clear benefit continue, and those who don't, stop.

• 09

  Erectile dysfunction is common and a vascular warning sign

  According to the Massachusetts Male Aging Study, over half of men over 40 have some trouble with erections, roughly 40% in their 40s and rising with each decade. Even 15–20% of men in their 20s and 30s are affected. Erections depend on blood flow, via nitric oxide and cyclic GMP, so smoking, diabetes, high cholesterol and high blood pressure all show up here. About 20–25% of long-distance cyclists notice numbness, pain or erectile problems from saddle pressure.

• 10

  Sperm counts are falling worldwide and men are half of infertility

  The largest recent update of sperm-count studies found declines on every continent, possibly speeding up over the last 20 years, alongside lower testosterone, earlier puberty in boys and more testicular cancer. A male factor is present in about 50% of infertile couples: 30% male only and 20% combined. Couples often rush to IVF without checking the man.