Condition deep-dive · 6 min read

Acute Mountain Sickness — supplement protocol for prevention

Updated 2026-05-19 · Reviewed by SupplementScore editors · No sponsorships

Acute mountain sickness (AMS) — headache, nausea, fatigue, disrupted sleep above ~2500 m — affects 25–40% of unacclimated travellers to standard altitude destinations and substantially more on rapid ascents. The supplement evidence is thinner than for many other conditions: gradual ascent is the foundation, acetazolamide (Diamox) is the first-line pharmacological prevention with strong trial weight, and most supplements have only modest signal. Ibuprofen has surprisingly good evidence for headache-component prevention. Iron status matters for both AMS susceptibility and high-altitude exercise performance.

HACE and HAPE are medical emergencies. AMS can progress to high-altitude cerebral oedema (HACE — ataxia, altered mental status) or high-altitude pulmonary oedema (HAPE — severe dyspnoea, cough, frothy sputum). Immediate descent is the treatment; supplements do not address these. Any deterioration, neurological symptoms, or severe shortness of breath at altitude warrants descent and medical evacuation. Pre-trip evaluation with travel medicine for serious high-altitude trips (above 4000 m) is strongly advised.

The foundation — acclimatisation strategy

The dose-response of altitude exposure to AMS is steeper than any pharmacological intervention. The accepted rule: above 2500–3000 m, ascend no more than 500 m/day in sleeping altitude, with a rest day every 1000 m. "Climb high, sleep low" — daytime exposure above your sleeping altitude promotes acclimatisation without the overnight hypoxic burden. Hydration, avoiding alcohol for the first 48 hours, and reduced exertion in the first day at altitude reduce AMS likelihood. This is by far the largest preventable risk factor.

The supplement and pharmacological stack

Layer 1 · First-line pharmacological (not a supplement, but worth including)

Acetazolamide (Diamox) — prescriber-directed

125 mg b.i.d. starting 1 day before ascent, continued through the highest sleeping altitude + 2 days

Strongest trial weight in AMS prevention; carbonic-anhydrase inhibitor that accelerates ventilatory acclimatisation. The Wilderness Medical Society guidelines recommend acetazolamide for moderate-to-high AMS risk profiles. Side effects include tingling fingers/lips, mild diuresis, taste changes. Sulfa-allergic patients should discuss with prescriber. Not a supplement — but supplements should not be expected to substitute for it in significant-risk scenarios.

Layer 2 · Best supplement-aisle signal

Ibuprofen 600 mg t.i.d. — for prophylaxis

600 mg three times daily, starting the day before ascent, continuing through high altitude

Lipman 2012 (Ann Emerg Med) trial showed ibuprofen 600 mg t.i.d. reduced AMS incidence vs placebo — comparable to acetazolamide in some comparisons. The mechanism may relate to prostaglandin-mediated cerebral vasodilation that contributes to AMS headache. Useful as a supplement-aisle alternative when acetazolamide is contraindicated or unavailable. Standard NSAID cautions (renal, GI, drug interactions).

Layer 2 · For iron-deficient travellers

Iron — if ferritin low

If ferritin <30 ng/mL: 25–65 mg elemental iron daily for 4+ weeks pre-trip

Iron deficiency is independently associated with reduced exercise capacity at altitude and may worsen AMS susceptibility. Talbot 2011 showed iron repletion improved high-altitude exercise capacity. Test ferritin pre-trip if symptomatic or risk-stratified; supplement if low. Don't add iron empirically without testing.

Layer 3 · Modest supplement signals

Ginkgo biloba

120 mg b.i.d., starting 5 days before ascent

Mixed trial evidence — some positive (Roncin 1996) and some negative (Gertsch 2004). The 2007 Gertsch head-to-head trial found ibuprofen and acetazolamide superior to ginkgo for AMS prevention. Modest signal at best; not a first-choice but reasonable in low-stakes recreational ascents if acetazolamide and ibuprofen are unavailable.

Layer 3 · Plausible mechanism, thin trial weight

Rhodiola rosea

200–400 mg/day standardised extract, starting 1 week pre-ascent

Traditional Russian high-altitude adaptogen; observational and small trial data on perceived exertion and adaptation at altitude. Not a first-line AMS prophylaxis; modest signal at best. Useful as a low-risk adjunct if other interventions aren't desired.

Layer 3 · For headache treatment

Acetaminophen / paracetamol — for AMS headache treatment

500–1000 mg as needed, up to 4 g/day

Once AMS headache develops, acetaminophen has trial-level evidence for treatment. Good alternative for those who cannot take NSAIDs. Doesn't prevent AMS but addresses the headache component.

The hydration and metabolic layer

Hydration to 3–4 L/day at altitude — increased respiratory rate and dry mountain air cause substantial insensible losses. Pale-yellow urine is the target.
Carbohydrate-emphasised diet — the brain's reduced oxygen efficiency at altitude is partly compensated by carbohydrate metabolism; 60%+ carb intake supports performance.
Alcohol minimisation for 48 hours at altitude — depresses ventilatory drive when you need maximum oxygenation.
Adequate sleep — periodic breathing at altitude disrupts sleep. Acetazolamide also improves sleep architecture at altitude; melatonin can help if circadian shift compounds the trip.

What to skip

Coca tea (mate de coca) as primary prevention — traditional Andean practice; modest signal for symptom relief. Not a substitute for acclimatisation strategy in significant ascents. Note: positive drug-screen implications for US travellers.
"Oxygen-boosting" supplements — chlorophyll, beetroot, etc. Beetroot has VO2max-modulation evidence at sea level but does not reliably prevent AMS.
Garlic supplements as "altitude prep" — no AMS-specific evidence.
Pseudo-stimulants and energy drinks — mask AMS symptoms while not addressing the underlying physiology.
Generic "altitude formula" blends — expensive combinations of unproven ingredients.

Risk-stratified planning

Low-risk (no prior AMS, slow ascent to <3500 m): Acclimatisation strategy + hydration. Supplements optional.
Moderate-risk (prior AMS, ascent to 3500–4500 m): Acetazolamide 125 mg b.i.d. or ibuprofen 600 mg t.i.d. Iron repletion if deficient.
High-risk (rapid ascent >4500 m, prior HAPE/HACE): Travel medicine consultation pre-trip. Acetazolamide ± dexamethasone (HACE prevention) under prescriber direction. Iron status optimised pre-trip.
Special situations (pregnancy, severe COPD, sickle cell, severe CV disease): Specialist evaluation pre-altitude exposure.

Practical quick-start. Plan ascent at no more than 500 m/day sleeping altitude above 2500 m. Hydrate to 3 L/day, minimal alcohol first 48 hours, reduce exertion day 1. For moderate-risk ascents, prescriber-directed acetazolamide 125 mg b.i.d. or ibuprofen 600 mg t.i.d. starting day before. Ferritin check pre-trip; supplement iron if low. For any neurological symptoms, severe dyspnoea, or persistent worsening — descend immediately.

Educational reference, not medical advice. Discuss any altitude-related medication or supplement plan with a qualified clinician — ideally travel medicine — before high-altitude travel. AMS can progress to fatal HACE/HAPE; descent is the definitive treatment.