Understanding the Amino Acid: Does Glycine Raise Your Blood Pressure?

October 7, 2025 •

4 min read

Recent Mendelian randomization analysis found that a genetically predicted higher level of circulating glycine is associated with lower systolic and diastolic blood pressure. This compelling evidence helps clarify the confusing historical debate surrounding the topic and answers the question: Does glycine raise your blood pressure? This article explores the science behind glycine's effects on cardiovascular health.

Quick Summary

Current evidence, including robust genetic studies, suggests that higher circulating levels of glycine correlate with lower blood pressure. This contradicts some older findings that linked dietary glycine from animal protein to increased BP. Glycine's protective effects are attributed to its antioxidant and anti-inflammatory roles, which support overall heart and vascular health.

Key Points

Conflicting Evidence: Older studies linking high dietary glycine from meat to higher blood pressure were likely flawed due to confounding factors, not glycine itself.
Cardioprotective Effects: Modern genetic studies show higher circulating glycine is associated with lower blood pressure, suggesting a protective role.
Mechanisms of Action: Glycine helps lower blood pressure by enhancing nitric oxide, fighting inflammation and oxidative stress, and promoting vasodilation.
Food Sources: Glycine can be found in high-protein animal products like bone broth and meat, as well as plant-based sources such as legumes, nuts, and seeds.
Supplement Safety: Glycine supplements are generally safe for most people at typical doses but can interact with some medications, including antipsychotics and blood pressure drugs.
Recommended Dosage: Typical supplemental doses used in studies range from 3 to 5 grams per day, though medical guidance is recommended.
Consult a Doctor: Always consult a healthcare professional before starting any supplement, especially if you have pre-existing health conditions or are on medication.

Conflicting Evidence: Untangling the Glycine and Blood Pressure Debate

The relationship between glycine and blood pressure has been a source of confusion, largely due to conflicting outcomes from different types of research. Some earlier observational studies suggested a potential link between higher dietary glycine intake and increased blood pressure, particularly in Western populations. These findings, however, came from cross-sectional studies that focused on glycine consumed from meat and animal protein, which are often associated with other dietary factors that can influence blood pressure. This made it difficult to isolate glycine's specific impact.

In contrast, newer and more robust research, such as Mendelian randomization studies, paints a clearer picture. These analyses found that higher circulating levels of glycine are actually linked to lower blood pressure. This suggests that the issue is not with glycine itself, but rather with the overall dietary context in which it is consumed. The adverse effects observed in older studies were likely attributable to the high intake of animal protein and other related factors, not the glycine content.

How Glycine Supports Healthy Blood Pressure

Emerging research indicates that glycine plays a protective role in cardiovascular health through several key mechanisms. These beneficial actions directly counteract factors that contribute to hypertension.

Enhancing Nitric Oxide Availability: Glycine helps increase the bioavailability of nitric oxide (NO), a crucial molecule that helps relax and widen blood vessels. This effect leads to lower blood pressure and improved vascular function.
Powerful Antioxidant Effects: As a component of glutathione, a major cellular antioxidant, glycine helps combat oxidative stress and the formation of free radicals. This protective action is crucial for maintaining the health and flexibility of blood vessels.
Anti-inflammatory Properties: Chronic inflammation is a known risk factor for cardiovascular disease and high blood pressure. Glycine exhibits anti-inflammatory properties, which can help mitigate the vascular damage caused by inflammatory molecules.
Activation of Chloride Channels: Studies have shown that glycine can activate glycine-gated chloride channels in the endothelium (the inner lining of blood vessels). This activation causes the cells to hyperpolarize, which decreases the likelihood of calcium channel opening, resulting in vasodilation and lower blood pressure.
Improved Elastin and Collagen Synthesis: Glycine is essential for the synthesis of collagen and elastin, structural proteins that maintain the integrity and elasticity of the aorta and other large vessels. Impaired elastin formation has been linked to the development of hypertension, so sufficient glycine intake may help preserve arterial flexibility.

Is Glycine Supplementation a Safe Option?

For most people, supplementing with glycine appears to be safe and well-tolerated at typical doses (around 3 to 5 grams per day). Studies have even used much higher doses (up to 90 grams per day) for short periods without serious side effects. However, some individuals might experience mild side effects like stomach upset.

High doses administered in clinical settings, such as during surgery, have been associated with more severe issues like visual disturbances and neurological symptoms, but this is not relevant for oral supplementation.

Drug Interactions and Precautions

While generally safe, it is crucial to consult a healthcare provider before starting glycine supplements, especially if you are taking other medications or have pre-existing health conditions. Glycine can interact with certain drugs:

Antipsychotics: High doses of glycine might decrease the effectiveness of some antipsychotic medications like clozapine.
Blood Pressure Medications: Since glycine has the potential to lower blood pressure, it may enhance the effects of antihypertensive drugs. Individuals taking blood pressure medication should monitor their levels closely under a doctor's supervision.

How to Increase Your Glycine Intake

Glycine can be obtained from both dietary sources and supplements. While the body can produce some glycine, studies suggest that dietary intake is often insufficient for optimal metabolic function, making supplementation a useful option for some.

Food Sources of Glycine:

Animal Sources: High-protein animal products are rich in glycine, including bone broth, chicken skin, red meat, fish, and gelatin.
Plant-Based Sources: Legumes, nuts, and seeds are also good sources. Options include peanuts, pumpkin seeds, hemp seeds, lentils, spinach, and soybeans.

Comparing Older vs. Modern Glycine Research


Research Aspect	Older Observational Studies	Modern Genetic & Mechanistic Studies
Research Design	Cross-sectional epidemiological studies linking dietary intake (from meat) to BP.	Mendelian randomization, animal models, in-vitro experiments.
Key Finding	Higher dietary glycine (primarily from animal protein) may be associated with slightly higher blood pressure in some populations.	Higher circulating glycine levels are associated with lower blood pressure.
Interpretation	The link was often misinterpreted, failing to control for the overall dietary context of high animal protein intake.	The protective effect of glycine is likely independent of other dietary factors and is a direct result of its physiological functions.
Mechanism	The mechanism was unclear and potentially linked to other components of animal protein.	Mechanisms identified include enhanced nitric oxide availability, antioxidant activity, and direct vascular effects.

Conclusion

Based on a growing body of robust evidence, the notion that glycine raises blood pressure is largely debunked. Newer, more reliable research indicates that higher circulating levels of glycine are associated with lower blood pressure and a reduced risk of hypertension. The confusion stemmed from early observational studies that failed to distinguish between the effects of glycine and other compounds found in high-protein animal foods. Glycine's protective cardiovascular effects are rooted in its roles as an antioxidant, anti-inflammatory agent, and vasodilator. While generally safe, individuals with pre-existing conditions or those on medication should always consult a healthcare provider before beginning supplementation. Increasing glycine intake through a balanced diet, potentially with supplementation under medical guidance, is a promising strategy for supporting overall heart health.

Frequently Asked Questions

While emerging research suggests glycine has a blood-pressure-lowering effect and a potential supportive role in hypertension management, it is not a primary or standalone treatment. You should always consult a healthcare provider for managing high blood pressure.

Glycine may potentially enhance the effects of some antihypertensive drugs, so it is critical for anyone on blood pressure medication to monitor their levels closely and consult their doctor before adding a glycine supplement.

Dietary glycine comes from food sources, while supplemental glycine is taken as a powder or capsule. Research shows that while dietary intake is often insufficient for optimal levels, supplements can effectively increase circulating glycine, which has been associated with lower blood pressure.

Glycine is a precursor to glutathione, a powerful antioxidant that helps neutralize free radicals and reduce oxidative stress. By protecting blood vessels from damage, this action helps maintain their flexibility and function, which contributes to lower blood pressure.

At standard supplemental doses (e.g., 3-5 grams per day), glycine is generally well-tolerated. Some individuals may experience mild stomach upset. Severe side effects are rare and typically associated with very high doses used in specific medical procedures.

Bone broth, meat (especially red meat and chicken), fish, and gelatin are high in glycine. Plant-based sources include legumes, nuts (peanuts, almonds), seeds (pumpkin, hemp), spinach, and cabbage.

Older studies were observational and often linked dietary glycine from animal protein to slightly higher blood pressure. However, these studies did not adequately control for other factors related to high animal protein diets, and more recent studies with better methods have shown that circulating glycine is protective.