Coca Leaf Does Not Effectively Prevent or Treat Altitude Sickness
Coca leaf products (tea or chewing) are not effective for preventing or treating acute mountain sickness and should not be recommended—multiple studies show they are associated with increased, not decreased, AMS risk. 1, 2
The Evidence Against Coca Leaf
The most compelling data comes from two cohort studies in Cusco, Peru (3,350-3,400m):
2022 study of 142 travelers: Coca leaf tea consumption was not associated with decreased AMS risk 1. In fact, 39% of participants developed AMS despite 34% using coca tea for prevention.
2012 study of 991 travelers: Using coca leaf products was associated with increased AMS frequency 2. AMS occurred in 48.5% of travelers, with 17.1% experiencing severe AMS. Notably, 62.8% used coca products versus only 16.6% who used acetazolamide—yet acetazolamide users had significantly lower AMS rates.
What Actually Works: Acetazolamide
The American Academy of Sleep Medicine (2025) recommends acetazolamide 250mg for high altitude exposure 3. This is supported by:
- Clinically meaningful improvements in disease severity (AHI, desaturation index) 3
- Moderate effect size with only trivial side effects (paresthesia, altered taste, increased urination) 3
- Proven efficacy: In the Cusco studies, acetazolamide was associated with an 87% reduction in AMS risk (OR 0.13) 1
For rapid ascents above 3,500m requiring immediate physical performance, doses of 500-750mg daily within 24 hours of exposure are most effective 4.
Why Coca Leaf Doesn't Work for AMS
While coca leaves may alter glucose metabolism during exercise (blocking glycolysis, promoting fatty acid oxidation) 5, this metabolic effect does not translate to AMS prevention. The cultural and traditional significance of coca in Andean populations is well-documented 6, 7, but there is no scientific evidence supporting its use for altitude illness in travelers.
Critical Risk Factors to Address
Instead of coca products, focus on these evidence-based interventions:
Prevention strategies:
- Gradual ascent (300-600m/day above 2,500m) 8
- Acetazolamide prophylaxis, especially for those with prior AMS history 1
- Adequate hydration and avoiding alcohol 9
High-risk populations requiring closer monitoring:
- Obese individuals (OR 14.45 for AMS) 1
- Women (OR 4.32 for AMS) 1
- Younger travelers (20-29 years) 2
- Daily smokers 10
Common Pitfall
The widespread use of coca products (used by 63% of travelers in one study) reflects poor pre-travel counseling—only 29% received physician advice about AMS, and only 19% were counseled about acetazolamide 2. Medical students from Latin American countries show similarly poor knowledge, with only 10% recognizing acetazolamide as appropriate prophylaxis 11.
Bottom line: Recommend acetazolamide 250mg (or 500-750mg for rapid ascents), not coca products, for AMS prevention in travelers ascending to altitudes above 2,500m.