Supplement analysis backed by scientific evidence · PT

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Limited evidencePhysical performance

Altitude Support Formulas

Rhodiola and antioxidant blends sold for acute mountain sickness. The one rigorous placebo-controlled trial of Rhodiola was negative and antioxidant vitamins have also failed; the positive data come mostly from Chinese-language trials of variable quality.

Evidence last reviewed: August 2026

What the science says

  • Rhodiola did not prevent acute mountain sickness Moderate evidence

    A randomized, double-blind, placebo-controlled crossover trial in 102 people ascending rapidly to 3,421 m found 800 mg/day of Rhodiola crenulata extract no better than placebo for either the incidence or the severity of acute mountain sickness.

  • A positive meta-analysis, but limited in scope Limited evidence

    A 2025 systematic review of 19 RCTs (1,690 participants), all conducted in China, found Rhodiola crenulata extract improved blood oxygen measures versus placebo but not versus conventional treatment, and the authors call for more rigorous trials.

  • Antioxidant vitamins do not prevent AMS Moderate evidence

    A double-blind, randomized, placebo-controlled trial found oral antioxidant supplementation did not prevent acute mountain sickness during high-altitude ascent.

Dosage & safety

Studied doseTrials used 800 mg/day of Rhodiola crenulata extract begun about a week before ascent. Commercial blends rarely disclose comparable standardisation.
SafetyRhodiola is usually well tolerated but can cause agitation and insomnia — unhelpful at altitude. None of these products replaces gradual ascent, and none should be relied on instead of acetazolamide or descent: altitude illness can be fatal.

Scientific references

Where to buy

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