SYMPTOMS
Hot flashes or night sweats
Everyday reasons for hot flashes, what to ask your doctor to check, and which nutrients have been studied.
Also described as: hot flash, hot flush, night sweat, flushes, flashes, perimenopaus, menopaus
Common everyday causes
Hormone shifts of perimenopause and menopause
Falling and swinging estrogen drives hot flashes, night waking, mood changes and lower libido, usually from the early 40s. Diagnosis is by symptoms and cycle changes; hormone tests swing too much to rely on. Ask your doctor about hormone therapy or non-hormonal options.
An overactive thyroid
Too much thyroid hormone speeds everything up: anxiety, a racing heart, poor sleep, heat intolerance, loose stools and hair shedding. Ask for TSH and free T4.
What’s been studied
- Vitamin E
For menopause transition.
- Magnesium
For menopause transition.
- Glycine
For menopause transition.
When to see a doctor first
- Chest pain, fainting or getting short of breath need a doctor today; call 911 if it’s happening now.
- Blood in stool, urine or vomit (or black stools) needs a doctor visit soon.
- Losing weight without trying should be checked by a doctor before anything else.
- Fevers or drenching night sweats need a doctor visit to find the cause.
- Sudden one-sided numbness, slurred speech or the worst headache of your life are emergencies; call 911 now.
- Any bleeding after periods have stopped for a year needs a doctor visit soon.
From the Journal
- Magnesium glycinate vs citrate vs oxide: which form should you take?
Glycinate, citrate, oxide, malate, threonate and taurate compared on magnesium content, absorption, gut comfort and capsule space, plus the 350 mg supplement limit and medicine timing.
- Which supplements help you sleep? What the research shows
Magnesium, L-theanine, melatonin, saffron, glycine and tart cherry: what the trials found, the doses studied, and when poor sleep is a reason to see a doctor instead.
apiece asks a few quick questions about hot flashes in its quiz to tell these causes apart, and suggests only ingredients studied for the likely ones.
Questions
What can cause hot flashes?
Common everyday reasons include menopause transition, overactive thyroid. A doctor can help find which applies to you.
What tests can help explain hot flashes?
Ask your doctor about: Diagnosis is by symptoms and cycle changes; hormone tests swing too much to rely on. Ask your doctor about hormone therapy or non-hormonal options; TSH and free T4.
Which supplements are studied for hot flashes?
Depending on the cause: Vitamin E, Magnesium, Glycine. Some only make sense with a lab result (for example iron only when ferritin is low).*
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This page is general information, not medical advice. Check with your doctor or pharmacist before starting a supplement, especially if you take medication, are pregnant or nursing, or have a health condition. Updated 2026-10-21.