NutriStack
Atenolol and Garlic Extract, a caution.
Aged garlic extract reduces systolic blood pressure by approximately 8 mmHg in hypertensives. Layered on atenolol, the combined effect can drive blood pressure below target, particularly in older patients prone to orthostatic symptoms.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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At a glance
- Substances
- Atenolol and Garlic Extract
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Moderate evidence
Caution
What is happening. Aged garlic extract reduces systolic blood pressure by approximately 8 mmHg in hypertensives. Layered on atenolol, the combined effect can drive blood pressure below target, particularly in older patients prone to orthostatic symptoms.
Mechanism. Organosulfur compounds in garlic enhance NO and H2S signaling, producing vasodilation. The hemodynamic effect adds to atenolol's beta1 blockade.
Recommendation. If you take atenolol, monitor your blood pressure for 2-4 weeks after starting garlic extract. Have your prescriber re-evaluate your atenolol dose if your readings consistently fall below your target range.
Sources (2)
- Ried K. Garlic Lowers Blood Pressure in Hypertensive Individuals, Regulates Serum Cholesterol, and Stimulates Immunity: An Updated Meta-analysis and Review. J Nutr. 2016;146(2):389S-396S. PMID 26764326
- Ried K, Frank OR, Stocks NP, Fakler P, Sullivan T. Effect of garlic on blood pressure: a systematic review and meta-analysis. BMC Cardiovasc Disord. 2008;8:13. PMID 18554422
Stack Score
How this pair moves the number.
Effect on the composite score
If both Atenolol and Garlic Extract are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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