Testosterone dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Testosterone is the best-tested hormone on this site. A study of 5,246 men settled the heart safety question. A review that pooled 36 studies in 8,480 women covers the half of people nobody talks about.
Evidence grade for Testosterone: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 1 completed trial, 5,246 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 5,246
- Human studies
- 1
- Found nothing
- 0
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA-approved in several forms for male hypogonadism, when a man's body makes too little testosterone. A Schedule III controlled substance in the United States. No testosterone product is approved for women in the United States. That is a known gap, not a verdict on the evidence.
10 effects reported, 6 unwanted, 4 wanted, by people using it, not a trial
Goal pages: Muscle and strength, Brain, memory and mood, Hormones and growth hormone, Heart and circulation, Sleep
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Testosterone is the main male hormone. It runs sex drive, muscle, bone, mood and sperm. When your body makes too little, a doctor can replace it with a gel or a shot. That is testosterone replacement therapy, TRT. It is approved for men with low levels. It has better human trial data than almost anything on this site. No product is approved for women in the US, even though trial data for women exists.
What people take it for
- More energy and less tiredness. This is the number one reason men ask for it.
- Sex drive and erections.
- Muscle and less fat.
- Better mood and sharper thinking.
- For women after menopause, low sex drive.
What studies in people showed
Start with the heart, because that was the fear. A trial called TRAVERSE put 5,246 men aged 45 to 80 with heart risk and low testosterone on the gel or a dummy gel. It ran for close to two years. Heart death, heart attack and stroke happened in 7.0 percent on testosterone and 7.3 percent on the dummy gel. No difference. The heart scare is over for replacement doses in men who are truly low. Now the benefit. In the T-Trials in older men, sex drive, sexual activity and erections all got better. Energy did not. The fatigue score did not move. Walking got better only when all three trials were pooled, 20.5 percent against 12.6 percent. Mood got a little better. So the thing men ask for most, energy, is the thing the trials did not deliver. The men in these trials had levels under 300 measured twice, fasting, in the morning. For women, 36 trials in 8,480 women, mostly after menopause, found sex drive, arousal, orgasm and pleasure all improved, and sexual distress went down. LDL cholesterol rose while HDL and triglycerides fell. That is the one thing it is tested for in women. One more fact. It shuts down your own sperm production. That is not a side effect, it is how it works.
What people report
Reports, not study results
The good
- Sex drive and morning erections come back, usually within weeks.
- Mood is steadier and the gym goes better.
- Body composition shifts over months, with training.
- Men who split their shots report fewer ups and downs across the week.
The bad
- Acne and oily skin, often in the first days after a big shot.
- Holding water, a puffy face, sore or puffy nipples.
- Mood swings, irritability and poor sleep at the peak, then a flat, tired feeling before the next shot. That is the peak and crash pattern from one big weekly dose.
- Testicles shrink and sperm count drops. Some men do not get fertility back.
- Blood gets thicker, which clinics check for with regular labs.
- Once you start, stopping is hard, because your own production has been switched off.
Where these come from: The sexual function, energy and heart results are from the trials that used a dummy gel. The peak and crash symptoms come from a 2026 practice review on injection timing that is cited on this page. The acne, water, mood, testicle and thick blood reports come from user forums, mostly r/Testosterone and r/trt, and from TRT clinic write-ups.
My bottom line
If your bloodwork, done right, says you are low, this is the real thing and the heart question is answered. If your levels are normal and you are just tired, the trials say it will not fix that. And if you are on the shot, split the weekly dose into two or three smaller ones. The reasoning is simple and the page walks through it, even though nobody has run that trial.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Testosterone has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Testosterone and male hormones5,246 people · 2 studies · 1 found nothing
- Heart attacks and strokes5,246 people · 1 study
- Getting strongerno headcount stated · 1 study · 1 found nothing
- Mood and anxietyno headcount stated · 1 study · 1 found nothing
- Energy and fatigueno headcount stated · 1 study · 1 found nothing
- Libido and sexual functionno headcount stated · 1 study · 1 found nothing
What people using it report
Real people telling you what happened to them. Nobody checked it, and the people who post are not a fair sample, so it cannot prove anything works. It is still the best guide on this page to what people actually do with Testosterone, what they expect, and what goes wrong. The full account, including the negative reports, is below.
27 of the 36 indexed goals have no study of any kind behind Testosterone
No study in people, animals or cells on this page reports a result for these. That does not prove Testosterone does nothing for them. It does mean anything you have heard about Testosterone and one of these did not come from a study cited here.
Show full evidence
What is Testosterone?
Testosterone is the best-tested hormone on this site. A study of 5,246 men settled the heart safety question. A review that pooled 36 studies in 8,480 women covers the half of people nobody talks about.
Testosterone has better proof in people than almost anything else here. It also has the most noise around it. So this page starts with what the big studies in people found.
On safety in men, the question is answered. The TRAVERSE study took 5,246 men aged 45 to 80. All had truly low testosterone, and all had heart disease or a high risk of it. Men on testosterone had no more heart deaths, heart attacks or strokes than men on a dummy gel. That fear hung over this treatment for ten years.
On benefits, the answer is narrow, not sweeping. In the T-Trials in older men, testosterone clearly helped sex drive, sexual activity and erections. It did not help energy. Walking distance only improved when three studies were lumped together. Mood got slightly better. That is real, but it is less than the ads suggest.
For women, the proof is better than the silence around it suggests. It points at one use, not general use. See below.
How does Testosterone work?
Testosterone is a steroid hormone the body makes from cholesterol. In men it is made mostly in the testicles, on a signal from the brain. Women make smaller amounts in the ovaries and adrenal glands. It works by attaching to the testosterone receptor inside cells, which changes which genes are switched on. The body turns some of it into two other hormones. One is DHT, a stronger form that drives much of its effect on scalp hair and the prostate. The other is estrogen, which drives much of its effect on bone, mood and sex drive in men. Taking testosterone tells the brain to stop sending its own signals to the testicles. That is why it lowers sperm count and shrinks the testicles.
What have studies in people found about Testosterone?
Some of the best proof on this site. A heart safety study in 5,246 men. A set of studies in older men. And a review that pooled 36 studies in 8,480 women.
- TRAVERSE, 5,246 men at risk of heart trouble: no more heart deaths, heart attacks or strokes on testosterone than on a dummy gel.
- A review that pooled 36 studies in 8,480 women: after menopause, every part of sexual function measured got better.
- In those same women, LDL, the bad cholesterol, went up. Total cholesterol, HDL and triglycerides went down. That is why the form and how you take it matter.
- T-Trials in older men: sex drive, sexual activity and erections clearly got better.
- T-Trials: energy did not get better. Walking distance only improved when three studies were lumped together, not in the study built to test it.
- Taking testosterone switches off the brain signals that drive sperm making. That matters a lot to anyone who may want children, and it is often poorly explained when the drug is prescribed.
What this does not tell you: TRAVERSE tested a gel, adjusted to keep blood levels in a set range. The men had truly low levels and a high heart risk. It does not say anything about doses above the normal range. It does not say anything about men whose testosterone is normal. The T-Trials found less than the ads claim. Sex got better, energy did not, and walking only improved when studies were lumped together. In women, the proof backs one use, and the form matters. None of this makes a case for testosterone in a man with a normal level who is tired. That is the most common reason people want it.
What do people who took Testosterone report?
This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.
- The practical discussion is overwhelmingly about schedule rather than amount. The standing position on these boards is that large injections every two weeks produce a peak and a trough that people describe feeling, and that smaller weekly or twice-weekly shots under the skin are what people move to. Stabilisation is described as taking around four to six weeks.
- Thickening blood, a rising haematocrit, is the problem raised more than any other, and the routine response described is periodic blood counts and giving blood or having blood drawn off once it climbs. It is treated as the thing that turns an uneventful protocol into a dangerous one, and unmonitored use is what posters warn about rather than the hormone itself.
- Oestradiol, the main estrogen, is discussed in both directions and this is a point experienced posters correct newcomers on constantly: pushing it down is described as producing its own set of problems, including low libido and mental fog, so the target described is a range rather than a floor.
- Testicular shrinkage is described as common enough to plan for, and the usual answer described is adding hCG. Acne, oily skin, hair loss and worsened sleep apnoea come up regularly.
- Stopping is described as the hardest part, with people reporting a prolonged period of feeling worse than before they started, measured in weeks to months. This is raised as the thing people underestimate going in.
- Where someone reports feeling no different, the answer given in these threads is almost always that their expectations were wrong or their monitoring was inadequate rather than that the treatment did nothing, which is a self-serving pattern in a forum built around it and is worth naming.
- Finding a clinician who will work this way, and paying for testing, dominate the access discussion, and self-ordered laboratory panels are a normal part of how people describe managing it.
Sources: Long-running testosterone protocol, side effect and monitoring threads on ExcelMale, found by site-restricted search and read in September 2026. This material is closer to accumulated board guidance than to individual experience reports, and is described as such above. Nothing is attributed to any specific post and no post is reproduced.
The state of the research
Two things are worth saying plainly about this drug. They point in opposite directions.
First, the heart scare was overdone. For ten years, testosterone had a cloud over it. That cloud came from watching people, not testing, and from one small study that was stopped early. TRAVERSE was the proper answer. It took 5,246 men at high heart risk, and it came back clean. Men who skipped treatment they needed because of that cloud were badly served.
Second, the benefit is narrower than the clinics selling it suggest. In the best studies, sex got better and energy did not. That matters, because feeling tired is the most common reason men ask for it. Nobody has shown it helps a man with a normal level and low energy. The studies took men whose levels were below 300 ng/dL, measured twice, fasting, in the morning. That careful testing is the step most often skipped.
For women, the gap is different. It is a failure of the system, not of the proof. There are 36 studies and a joint statement backed by eleven medical groups. Yet in most countries there is no approved product for women. So women get prescribed a small part of a men's product, with no label to guide the dose.
The evidence, in charts
Fig. 1a · how many people
5,246people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| New England Journal of Medicine 2023 | 5,246 | 100% |
The whole total is one study of 5,246. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 1 more study in people gives no headcount and is not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
2 of 5 sources here are studies in people. The rest are not.
- Study in people · done in people240%
- Review of studies · sums up other studies360%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 4 different years, 2016 to 2026, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Approved
UK
Approved
AU
Approved
CA
Approved
Approved in all four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 5 · what the molecule is
- Kind of compound
- Hormone
- Molecule weight
- 288.4 Da. A steroid, not a peptide.
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: Free testosterone itself clears in minutes to hours. What determines dosing is the ester: cypionate and enanthate run roughly eight days, propionate under a day, and undecanoate several weeks. The ester pages cover what that means in practice.
No amino acid sequence is on file for Testosterone, which is expected: a hormone is not built from amino acids.
The studies we cite
- Study in people2023Cardiovascular safety of testosterone-replacement therapy
Testosterone did not raise the risk of heart attacks or strokes in the men most likely to have one. More than 5,000 men aged 45 to 80 took part. All had low testosterone with symptoms, and all were already at risk of heart trouble. Half rubbed on a testosterone gel and half a dummy gel. After about three years, heart deaths, heart attacks and strokes were about as common in each group. This was a gel held to a target blood level, not a home shot.
TRAVERSE. 5,246 men aged 45 to 80 with preexisting or high risk of cardiovascular disease, symptoms of hypogonadism and two fasting testosterone levels below 300 ng/dL, randomised double-blind to transdermal testosterone gel titrated to 350 to 750 ng/dL or placebo. Mean treatment 21.7 months, mean follow-up 33.0 months. Primary composite of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke occurred in 182 (7.0%) on testosterone and 190 (7.3%) on placebo, hazard ratio 0.96 (95% CI 0.78 to 1.17), p < 0.001 for non-inferiority.
- Study in people2016Effects of testosterone treatment in older men
Testosterone helped older men with sex and did much less for everything else. It raised their levels to what a man in his twenties or thirties would have. Sex drive, sexual activity and erections all clearly got better. Energy did not get better at all. Walking distance only improved when three studies were lumped together, which is a weaker way to find a result. Mood was slightly better. Side effects were no more common than on the dummy gel.
The T-Trials. Treatment raised testosterone into the mid-normal range for men aged 19 to 40. Sexual activity, sexual desire and erectile function all improved significantly. Vitality did not improve on the fatigue scale. The proportion improving 6-minute walking distance by at least 50 m did not differ in the Physical Function Trial but did when all three trials were pooled, 20.5% against 12.6%, p = 0.003. Mood and depressive symptoms were slightly better. Adverse event rates were similar.
- Review of studies2019Safety and efficacy of testosterone for women: a systematic review and meta-analysis of randomised controlled trial data
A review that pooled 36 studies in 8,480 women. After menopause, testosterone made sex better in every way measured, including desire, arousal, orgasm and pleasure, with less distress. Cholesterol shifted. LDL, the bad kind, went up, while HDL and triglycerides went down.
36 randomised controlled trials, 8,480 participants. In postmenopausal women testosterone significantly improved satisfactory sexual event frequency (mean difference 0.85, 95% CI 0.52 to 1.18), sexual desire (SMD 0.36), pleasure, arousal, orgasm, responsiveness and self-image, and reduced sexual concerns and distress. Lipids moved: LDL cholesterol rose while total cholesterol, HDL cholesterol and triglycerides fell.
- Review of studies2019Global consensus position statement on the use of testosterone therapy for women
A joint statement from eleven medical groups, including menopause and hormone societies. It is the go-to guide for what testosterone in women is backed for, and what it is not.
A consensus statement endorsed by eleven bodies including the International Menopause Society, The Endocrine Society, The North American Menopause Society and the Royal College of Obstetricians and Gynaecologists. The reference document for what testosterone therapy in women is and is not supported for.
- Review of studies2026Individualizing injectable testosterone replacement therapy in primary care: pharmacokinetics, symptom stability, safety monitoring, and injection interval
A 2026 guide for family doctors. It says the gap between shots is often picked out of habit. Short-acting forms make blood levels swing up and down between shots, more so with big doses and long gaps. A shot every two weeks should not be the default. If symptoms come and go, the timing may be the problem, not the weekly amount.
States that the interval between injections is sometimes chosen out of habit rather than clinical reasoning, that short-acting esters produce meaningful swings in serum exposure across the cycle especially at larger doses and longer intervals, and that every-two-week dosing should not be the automatic default. Where symptom cycling persists, the issue may be dose timing and peak-to-trough variation rather than an inadequate weekly total.
Common questions
Has Testosterone been tested in people?
Yes. 5,246 people given it across 1 completed trial cited here, 0 of which found nothing. Testosterone is the best-tested hormone on this site. A study of 5,246 men settled the heart safety question. A review that pooled 36 studies in 8,480 women covers the half of people nobody talks about.
What is the Testosterone dosage?
Approved medicine. No human dose established for unlabelled uses. Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose. FDA-approved in several forms for male hypogonadism, when a man's body makes too little testosterone. A Schedule III controlled substance in the United States. No testosterone product is approved for women in the United States. That is a known gap, not a verdict on the evidence.
Is Testosterone FDA-approved?
FDA-approved in several forms for male hypogonadism, when a man's body makes too little testosterone. A Schedule III controlled substance in the United States. No testosterone product is approved for women in the United States. That is a known gap, not a verdict on the evidence.
Does testosterone cause heart attacks?
The best study says no. TRAVERSE took 5,246 men who had heart disease or a high risk of it. Heart deaths, heart attacks and strokes happened to 7.0 percent on testosterone and 7.3 percent on a dummy gel. That question hung over this drug for ten years. It is now answered for normal replacement doses in men whose levels are truly low.
Will it fix my fatigue?
Probably not, and this is the most useful thing on the page. In the T-Trials, sex drive, sexual activity and erections clearly got better. Energy did not get better at all. Feeling tired is the most common reason men ask for testosterone, and it is the one thing the studies could not move.
What about testosterone for women?
It has more proof than most people realise, for one thing. A review that pooled 36 studies in 8,480 women found that after menopause, sex drive, arousal, orgasm, pleasure and satisfying sex all got better, with less distress. LDL, the bad cholesterol, went up while HDL and triglycerides went down, so the form matters. A statement backed by eleven medical groups sets the limits. Most countries still have no approved product for women.
Will it make me infertile?
It lowers sperm count. That is not a side effect. It is exactly what you would expect. Taking testosterone switches off the brain signals that drive sperm making. It usually comes back after stopping, but not always. It is also the fact most often poorly explained when the drug is prescribed. If you might want children, bring it up before the first shot, not after.
Is one injection a week the right schedule?
Often it is fine, but it should not be automatic. Cypionate and enanthate are short-acting forms. A big dose with a long gap gives high levels early and low levels late. The pages on those two forms explain how the level rises and falls, and what splitting the same weekly amount does.