Testosterone
Testosterone, TRT
and enclomiphene.
Testosterone
- Men & women
- Both need testosterone
- 6
- Things that lower it
- Labs first
- Then decide with your doctor
Low testosterone: what shuts it down
In simple words: the same stressors that cause insulin resistance also lower testosterone. Fixing them often raises it naturally. Before starting testosterone, ask your doctor about keeping your own production working.
Insulin resistance and belly fat
Fat tissue turns testosterone into estrogen, and high insulin lowers SHBG and the brain's signal (LH) that tells the testes to make testosterone.
Metabolic syndrome and type 2 diabetes
Men with these have low testosterone far more often. Low testosterone then makes it easier to gain fat: a vicious circle.
Chronic stress and high cortisol
Long-term high cortisol turns down the brain-to-testes signal (the HPG axis), so less testosterone is made.
Poor sleep and sleep apnea
Most testosterone is made during deep sleep. Short sleep or untreated sleep apnea lowers it.
Alcohol, opioids and some medicines
Heavy drinking, opioid pain medicines and some other drugs lower testosterone. Ask your doctor to review your list.
Eating too little or overtraining
Big calorie deficits and too much hard training without recovery can lower testosterone, including on a GLP-1.
The good news: losing belly fat, lifting weights, sleeping 7–9 hours, treating sleep apnea and lowering daily stress can all raise testosterone, often meaningfully.
Why TRT shuts down your own production
Your brain checks how much testosterone is in your blood. When testosterone comes from outside (gels, injections, pellets), the brain stops sending its signals (LH and FSH) to the testes.
Without those signals, the testes make much less of their own testosterone and sperm. That can mean smaller testes and lower fertility, and it can take months to recover after stopping, sometimes longer.
If you may want children, say so before starting TRT. It changes which options make sense.
Ask about these before TRT
For some men, especially younger men or those who want to keep fertility, doctors use medicines that make your body produce more of its own testosterone instead of replacing it:
- Enclomiphene or clomiphene block estrogen's brake on the brain, so it sends more LH and FSH and the testes make more testosterone and sperm. Clomiphene is used off-label for this; enclomiphene is not FDA-approved and is usually compounded.
- hCG acts like LH directly on the testes. It's sometimes used alone or alongside TRT to protect testicular function.
These are prescription decisions with their own side effects and monitoring (for example mood or vision changes, and blood count and estrogen checks). They don't suit everyone, and they don't work if the testes themselves are the problem. No doses are given here.
“TRT thickens your blood”: fact or fiction?Hematocrit is the share of your blood made of red blood cells.
With TRT: fact.
Testosterone tells your body to make more red blood cells. With TRT, hematocrit rising too high (thicker blood) is one of the most common side effects, especially with injections. Very thick blood may raise the risk of clots, though how much is still debated.
That's why guidelines check hematocrit before starting, at 3–6 months, then yearly, and your doctor lowers the dose or pauses treatment if it goes above about 54%.
With enclomiphene: much less common, but not zero.
Enclomiphene raises your own testosterone, usually into the normal range rather than above it, so big jumps in hematocrit are less common than with TRT. The research is smaller, so your doctor should still check a blood count.
Other things that also raise hematocrit: untreated sleep apnea, smoking, dehydration and living at high altitude.
Labs to ask your doctor about
- Total and free testosterone, drawn in the morning (repeat to confirm a low result)
- LH and FSH: show whether the problem starts in the brain or the testes
- Estradiol, SHBG and prolactin
- CBC (hematocrit), plus PSA when appropriate for your age
- Fasting glucose and insulin (HOMA-IR), HbA1c and lipids
Women make testosterone too, but testing and treatment are different; see why women need testosterone too. Educational only: PepFit Coach does not diagnose, prescribe or recommend doses.
Why women need testosterone too
In simple words: women make testosterone too, in much smaller amounts, from the ovaries and adrenal glands. It helps with sex drive, energy, mood, muscle strength and bone health.
What lowers it in women
- • Age: by their 40s many women have about half the testosterone they had in their 20s.
- • Surgical menopause (ovaries removed) causes a sudden drop.
- • Birth control pills raise SHBG, which lowers free testosterone.
- • Chronic stress, very low calorie diets and overtraining.
Low sex drive, tiredness and low mood have many causes (thyroid, iron, sleep, perimenopause), so test before assuming it's testosterone.
Too much is a problem too: PCOS
The most common hormone issue in women is too much testosterone, usually from PCOS: acne, extra facial or body hair, irregular periods and insulin resistance. That's treated very differently, often starting with insulin resistance (training, diet, and sometimes metformin or a GLP-1).
Treatment for women is different
- • An international consensus (2019) supports testosterone for women mainly in one case: postmenopausal women with low sexual desire that causes distress, using small doses that keep levels in the normal female range, usually a skin cream or gel.
- • No testosterone product is FDA-approved for women in the US, so it's prescribed off-label.
- • It isn't recommended just for energy, weight loss or muscle.
- • Too much can cause acne, extra hair, hair loss and a deeper voice, which may be permanent.
- • Men's TRT and enclomiphene don't apply to women. (Clomiphene is used in women for a different reason: to help with ovulation and fertility.)
Labs for women to ask about
- Total testosterone, ideally measured with a sensitive method (LC-MS/MS), plus SHBG
- Free testosterone or free androgen index
- DHEA-S, estradiol, prolactin and TSH
- FSH and LH (timed to your cycle if you still have periods)
- Fasting insulin and glucose (HOMA-IR) if PCOS is possible
Educational only. No doses are given; decide on any hormone treatment with your doctor.
Ready to test? Get the doctor letter with the right hormone labs for you.