Does TRT cause or worsen sleep apnea?
TRT and sleep apnea are linked, but the effect of testosterone looks small and may not last. In the one careful trial, breathing at night got worse for a few weeks in men who already had severe sleep apnea. By 18 weeks, the difference was no longer clear.
The link runs both ways. Untreated sleep apnea can lower testosterone, and testosterone may make sleep apnea a bit worse. It’s one of the checks in our guide to TRT side effects, and worth raising when you’re starting TRT.
Obstructive sleep apnea means your upper airway keeps closing or narrowing while you sleep. Your breathing stops or gets shallow, your oxygen drops, and you wake briefly, often without knowing it.
What did the one clinical trial find?
The best evidence comes from a single trial in Australia. It included 67 men with obesity and severe sleep apnea. For 18 weeks they got testosterone injections or placebo, and everyone followed a low-calorie diet.
Each man had overnight sleep studies at the start, at 7 weeks and at 18 weeks. The researchers counted how often blood oxygen dropped each hour, and how long it stayed below 90%.
At 7 weeks, men on testosterone had about 10 more oxygen drops per hour than men on placebo. They also spent about 6 percentage points more of the night below 90% oxygen.
At 18 weeks, the gaps had shrunk to about 4.5 drops per hour and 3 points. Neither was clearly different from zero. The authors called it a mild, time-limited worsening, no matter what a man’s starting testosterone was.
“Breathing got worse at 7 weeks, then the gap faded by 18 weeks, in the one careful trial we have.”
Follow-up reports from the same trial found that testosterone raised sexual desire. It didn’t change erections, quality of life or thinking tests. The authors wrote that small gains would need to be weighed against possible harm to breathing.
A smaller part of the study looked at why. It found no clear difference between the groups in the body’s breathing response to carbon dioxide.
Some changes did track with the 7-week worsening, so the researchers suggested a brief shift in that response. That’s still a theory.
What are the limits of that trial?
It’s one study, with 67 men, over 18 weeks. Everyone had obesity and severe sleep apnea, so it tells us less about men with mild or no sleep apnea.
Both groups were also losing weight, which can improve sleep apnea by itself. And the trial used a long-acting injection, not the weekly cypionate or enanthate most men use. So we can’t be sure the same timing applies to other types.
Reviews published since then reach a similar view. One called testosterone’s role in sleep apnea likely small and possibly time-limited. Another said the data on TRT in men with sleep apnea are limited.
What do guidelines and drug labels say?
The Endocrine Society’s 2018 guideline recommends against starting testosterone in men with untreated severe obstructive sleep apnea. It doesn’t give a specific rule for mild, moderate or treated sleep apnea.
The same guideline lists new or worse sleep apnea as an uncommon effect with weak evidence. It also notes that sleep apnea has been rare in testosterone trials.
The American Urological Association’s guideline found very little data on sleep apnea, so it makes no specific recommendation. It does list sleep apnea as one cause of a high red blood cell count.
| Source | What it says about sleep apnea |
|---|---|
| Endocrine Society guideline | Don’t start testosterone in untreated severe sleep apnea |
| AUA guideline | Too little data; sleep apnea can raise hematocrit |
| Xyosted label | May worsen sleep apnea, especially with obesity or lung disease |
| AndroGel 1.62% label | May worsen sleep apnea in some men with risk factors |
| Azmiro label | May worsen sleep apnea; tells patients it can |
| DEPO-Testosterone label | No mention of sleep apnea |
The older DEPO-Testosterone label doesn’t mention sleep apnea at all. Newer labels do. Guidelines treat it as a concern for every type of testosterone.
In one year-long Xyosted study of 150 men, 2% reported sleep apnea. There was no placebo group, so it’s hard to know how many cases were caused by the drug.
Who is more likely to have trouble?
The labels name two main risk factors: obesity and chronic lung disease. The National Heart, Lung, and Blood Institute adds others:
- Older age
- Extra weight, especially around the neck
- A large neck, tongue or tonsils
- Hormone conditions
- Being male, since sleep apnea is more common in men
Snoring alone doesn’t mean you have sleep apnea. But loud snoring with pauses or gasping is a classic sign.
If any of these apply to you, tell your prescriber before you start. A partner’s report helps too, since you may not notice your own snoring or pauses. Even a short note of what they’ve seen gives your prescriber something to go on.
Can sleep apnea cause low testosterone?
It can go along with it. A review of 18 studies found men with sleep apnea had lower testosterone than men without it. The gap was clear in severe sleep apnea, but not in mild or moderate cases.
A second review of 24 studies found the same pattern. But the studies varied a lot. A large study of 623 men then found the link mostly disappeared once age and body weight were taken into account.
Its authors concluded that weight, rather than sleep apnea itself, drives the testosterone level. Still, a low reading in a man with untreated sleep apnea may partly reflect the apnea.
The Endocrine Society lists sleep apnea among things that affect testosterone results. Which comes first, testing or treating, is your prescriber’s call.
Does the type of testosterone matter?
We don’t know. No study has compared gels, injections or pills for sleep apnea. The one trial used a long-acting injection given every few weeks.
The newer labels for a gel and two injections carry much the same warning. Guidelines don’t single out any product. So for now, the safest reading is that the concern applies to every type.
If you change products and your sleep changes, note when it started. That timing helps your prescriber sort out what’s going on.
Does CPAP raise testosterone?
Probably not. CPAP is a mask that keeps your airway open with gentle air pressure while you sleep. Two pooled reviews, of 232 and 388 men, found it did not clearly change testosterone levels.
One expert review said CPAP may help erections and possibly testosterone, but only when used every night. In practice, many people struggle with it: in one clinic review of men on TRT with high hematocrit and sleep apnea, about half used their CPAP poorly.
So think of CPAP as treatment for your breathing, not your testosterone. Many men use CPAP and TRT together. The guideline’s concern is sleep apnea that is severe and untreated.
Could sleep apnea explain high hematocrit on TRT?
It might. Hematocrit is the share of your blood made of red cells. Testosterone raises it, and low oxygen at night can push it up too.
One clinic reviewed 474 men on TRT. Those with sleep apnea had about twice the odds of a high hematocrit, even after allowing for age and weight. The authors suggested that sleep apnea be strongly considered when hematocrit climbs.
The Endocrine Society says the same: if hematocrit goes above 54%, look for low oxygen and sleep apnea. The AUA says a high hematocrit before starting should be explained first, and lists sleep apnea as a possible cause. Our page on hematocrit explains the test and its ranges.
How would you know if you have sleep apnea?
Many people don’t know until someone tells them. The National Heart, Lung, and Blood Institute and MedlinePlus list these signs:
| At night | During the day |
|---|---|
| Loud, frequent snoring | Sleepiness or tiredness |
| Breathing that stops and starts | Waking up unrefreshed |
| Gasping or choking | Morning headaches |
| Waking often to urinate | Low sex drive |
| Dry mouth on waking | High blood pressure that’s hard to treat |
Doctors often screen with a short questionnaire called STOP-Bang. It asks eight yes-or-no questions:
- Snoring: do you snore loudly?
- Tired: are you often tired or sleepy in the daytime?
- Observed: has anyone seen you stop breathing in your sleep?
- Pressure: do you have high blood pressure, or take pills for it?
- BMI: is your body mass index over 35?
- Age: are you over 50?
- Neck: is your neck over 40 cm (about 16 inches) around?
- Gender: are you male?
A score of 0 to 2 means low risk, and 5 to 8 means high risk. Being male already counts for one point. A quiz can’t diagnose sleep apnea, though; it only helps decide who needs a test.
Do you need a sleep study before TRT?
That’s a question for your prescriber. Guidelines don’t ask for a sleep study in every man. But if you have signs of sleep apnea, testing before you start makes sense to ask about.
The American Academy of Sleep Medicine says there are two ways to test. A home sleep test works for many adults who likely have moderate or severe sleep apnea. A lab study is better for people with heart or lung disease, a past stroke, or long-term opioid use.
A home test means wearing a small device overnight in your own bed. It tracks your breathing and blood oxygen. If a home test is negative or unclear but signs remain, the guideline recommends a full lab study.
A lab study, called polysomnography, also tracks brain waves, heart rate and movement. It can show which type of sleep apnea you have and how serious it is.
A sleep study gives an apnea-hypopnea index, or AHI. That’s the number of pauses or shallow breaths per hour of sleep. Mild is 5 to under 15, moderate is 15 to 30, and severe is over 30.
What should you ask your prescriber?
Bring these to your next visit. Our guide on how to prepare for a TRT appointment has more.
- Do my symptoms suggest I should have a sleep test before or during TRT?
- If I already use CPAP, does that change anything about my plan?
- Which signs should I report, and how soon?
- If my hematocrit rises, will you check for sleep apnea?
- When should my next blood test be? Our blood test timing tool can help you plan it.
When is it urgent?
Call your prescriber soon if a partner sees you stop breathing, or you wake up gasping or choking. Do the same if you get so sleepy you nod off while driving or at work. Don’t drive while you feel that drowsy.
Call 911 if you have chest pain, or trouble breathing while you’re awake. Those need care right away, whatever the cause.
How can you keep track of sleep on TRT?
Short, regular notes make changes easier to spot. Write down how you slept, how rested you feel, and any snoring or gasping a partner mentions.
TRTracker lets you log a quick daily check-in next to your doses and lab results. It doesn’t diagnose sleep apnea, so share anything worrying with your prescriber.