Can melatonin lower blood pressure (hypertension)?

Melatonin's Effect on Blood Pressure

Melatonin supplementation may modestly reduce blood pressure, particularly nocturnal blood pressure, but it is not recommended as a primary treatment for hypertension according to current guidelines. 1

Evidence for Melatonin's Blood Pressure-Lowering Effects

The relationship between melatonin and blood pressure has been studied with the following findings:

• Controlled-release melatonin has shown a modest reduction in asleep systolic blood pressure by approximately 3.57 mmHg, though this finding was not statistically significant 2
• Lower physiologic levels of melatonin may be an independent risk factor for developing hypertension, as women with higher urinary melatonin levels had a 51% lower risk of developing hypertension over 8 years 3
• Melatonin production is often reduced in hypertensive individuals 4
• Animal studies have demonstrated antihypertensive effects of melatonin in spontaneously hypertensive rats 5

Mechanisms of Action

Melatonin may lower blood pressure through several mechanisms:

• Improving endothelial function by increasing nitric oxide availability through its antioxidant properties 4
• Modulating the autonomic nervous system by decreasing sympathetic tone and increasing parasympathetic activity 4
• Acting on specific melatonin receptors in peripheral blood vessels and central nervous system regions involved in blood pressure regulation 4

Current Guideline Recommendations

Despite these potential benefits, major hypertension guidelines do not recommend melatonin as a primary treatment for hypertension:

• The 2020 International Society of Hypertension guidelines recommend established antihypertensive medications including ACE inhibitors, ARBs, calcium channel blockers, and thiazide diuretics as first-line treatments 6
• The 2024 European Society of Cardiology guidelines recommend these same established medications that have demonstrated effective reduction of blood pressure and cardiovascular events in randomized controlled trials 6
• For resistant hypertension, guidelines recommend adding spironolactone, eplerenone, beta-blockers, or other established medications rather than supplements 6

Safety Considerations

Melatonin is generally considered safe for short-term use:

• The Society for Perioperative Assessment and Quality Improvement consensus statement indicates that melatonin can be safely continued in the perioperative period 6
• Melatonin has been shown to improve sleep efficacy and total sleep time 2
• No major adverse effects have been reported in clinical trials of melatonin for blood pressure management 2

Limitations of Current Evidence

The evidence supporting melatonin for hypertension has important limitations:

• Small number of high-quality trials with limited sample sizes 2
• Lack of data on cardiovascular outcomes and long-term effects 2
• Uncertainty regarding optimal dosing and formulation (controlled-release vs. immediate-release) 4
• Inconsistent findings across different patient populations 2

Clinical Implications

For patients interested in using melatonin for blood pressure management:

1. Melatonin should not replace established antihypertensive medications
2. Controlled-release formulations may be more effective than immediate-release for blood pressure effects
3. Patients with non-dipping blood pressure patterns (insufficient nighttime BP decrease) may potentially benefit more
4. Regular blood pressure monitoring is essential if adding melatonin to a treatment regimen

Bottom Line

While melatonin shows some promise in blood pressure regulation, particularly for nocturnal hypertension, current evidence is insufficient to recommend it as a primary treatment for hypertension. Established antihypertensive medications with proven cardiovascular outcome benefits should remain the cornerstone of hypertension management.