Hormones & Testosterone

Clear explanations of testosterone, cortisol, thyroid and other hormones that shape men's health.

PSA Levels by Age: Normal Ranges, What Raises PSA and When to Get Tested

Short answer: PSA (prostate-specific antigen) normally creeps up as men get older, so a value that is unremarkable at 70 can deserve a closer look at 45. In a large Mayo Clinic study of healthy men, 95% had a PSA at or below about 2.0 ng/mL in their 40s, 3.0 in their 50s, 4.0 in…

Metformin Side Effects in Men: What Is Common, What Is Rare and When to Call a Doctor

Short answer: The most common metformin side effects in men are the same as in women: diarrhea, nausea, gas and stomach upset, which usually show up when you start or raise the dose and often settle with time, food and a slower dose increase. Long-term use can lower vitamin B12, so periodic testing is worth…

Tribulus Terrestris Benefits for Men: What Human Research Really Shows

Short answer: The best documented tribulus terrestris benefits are modest and uncertain. Controlled human trials mostly show no meaningful rise in testosterone, no gain in strength or muscle in athletes, and sexual function results that are mixed and often no better than placebo. Tribulus is usually well tolerated in short trials, but high doses and…

Horny Goat Weed Benefits for Men: What the Research Actually Shows

Short answer: The best documented horny goat weed benefits in people are modest and narrow: one 24-month randomized trial found that epimedium flavonoids helped preserve bone density in postmenopausal women. The benefits most men are curious about (sexual function, drive and testosterone) rest mainly on rat, mouse and test tube studies, and a 2022 review…

Foods That Boost Testosterone: What the Evidence Actually Shows (and Foods That Lower It)

Short answer: No single food raises testosterone the way a medication does, but a few foods help by fixing shortfalls the body needs for normal hormone production. The best supported picks are zinc-rich foods (oysters, beef, crab, pumpkin seeds), vitamin D sources (salmon, trout, eggs, fortified milk), extra virgin olive oil and an overall diet…

Low DHEA Symptoms in Men: DHEA-S Levels, Testing and Whether DHEA Supplements Help

Short answer: Low DHEA symptoms in men are vague: lower sex drive, erectile problems and fatigue are the ones most often linked to it, but these overlap with many other causes. A low DHEA-S blood result is most often a normal part of aging, and less often a sign of an adrenal or pituitary problem…

Varicocele Symptoms and Low Testosterone: What the Evidence Shows

Short answer: The most common varicocele symptoms are a dull ache in the scrotum that gets worse when standing and eases when lying down, a lump that can feel like a “bag of worms” above the testicle (usually on the left), a smaller testicle on the affected side, and trouble conceiving. Many varicoceles cause no…

Does a Vasectomy Lower Testosterone? Side Effects, Recovery and What Changes

Short answer: No. A vasectomy does not lower testosterone. The procedure blocks the tubes that carry sperm (the vas deferens), but the testicles keep making testosterone and release it straight into the bloodstream, so hormone levels, sex drive and erections are not affected.[1][2] The real side effects are local and short term (swelling, bruising, soreness),…

Signs of Low Testosterone in Men: Symptoms, Testing and When to See a Doctor

Signs of low testosterone include fatigue, reduced drive, and mood changes. Learn key symptoms, common misconceptions, and options for natural support.

Sleep Apnea and Testosterone: How Low T and OSA Are Linked

Short answer: Sleep apnea and testosterone are linked in both directions. Men with obstructive sleep apnea (OSA) tend to have lower testosterone, and the strongest shared driver is excess body fat, while repeated oxygen drops and broken sleep may also suppress the hormone signals that tell the testes to make testosterone. Treating apnea with CPAP…

Insomnia in Men: Sleep Debt, Testosterone and What Actually Helps

Short answer: Insomnia in men is a real sleep disorder, not a willpower problem, and it often travels with sleep debt that can nudge testosterone down. In a well known JAMA study, one week of sleeping under 5 hours a night lowered daytime testosterone by 10 to 15% in healthy young men. The first line…

Normal Testosterone Levels by Age: Chart and What Your Number Means

Short answer: For adult men, normal testosterone levels usually fall somewhere between about 250 and 900 ng/dL, depending on the lab and the reference population. The American Urological Association (AUA) uses a total testosterone below 300 ng/dL as a reasonable cutoff for low testosterone, but only when it shows up on two early morning tests…

Best Time to Check Testosterone Levels (and How to Prepare)

Short answer: The best time to check testosterone levels is early morning, ideally between 7 and 10 a.m. or within about three hours of waking, when levels are typically at their daily high. Many labs and guidelines prefer a fasting sample, and one low result is never enough: major guidelines ask for two separate early…

Opioids and Low Testosterone: Opioid-Induced Androgen Deficiency Explained

Short answer: Yes, long-term opioid use can lower testosterone in men. Researchers call this opioid-induced androgen deficiency (OPIAD): opioids act on the brain’s hormone control centers and reduce the signals that tell the testes to make testosterone. Reviews of men on long-term opioids for chronic non-cancer pain report rates from 19% to 86%, depending on…

Fatty Liver and Testosterone: The MASLD Link in Men

Short answer: Fatty liver and testosterone are linked. Men with fatty liver disease (now called MASLD, metabolic dysfunction-associated steatotic liver disease) have, on average, lower total testosterone than men without it, and both problems grow out of the same metabolic soil: excess belly fat, insulin resistance and the rest of metabolic syndrome. The studies are…

High Estrogen in Men: Signs, Causes, Testing and Treatment

Short answer: High estrogen in men usually means a high level of estradiol, the main estrogen, or estrogen that is high relative to testosterone. The most recognized signs are enlarged or tender breast tissue (gynecomastia), lower sex drive, erection problems and fertility problems. Common drivers include excess body fat, certain medications, testosterone or anabolic steroid…

High Prolactin in Men: Symptoms, Causes, Normal Levels and Treatment

Short answer: High prolactin in men (hyperprolactinemia) means the blood level of prolactin, a pituitary hormone, is above the normal range, which for men is usually under 20 ng/mL. It can lower testosterone and cause low sex drive, erection problems, breast enlargement, infertility and, with a larger pituitary tumor, headaches or vision changes. The most…

High SHBG in Men: Causes, Normal Range and How to Lower SHBG

Short answer: High SHBG in men means the liver is making more sex hormone binding globulin, the protein that grips testosterone and keeps it inactive in the blood. As SHBG rises, less of your total testosterone is free for tissues to use, so a man can have a “normal” total testosterone result and still have…