Does niacinamide improve blood flow? A critical look at vitamin B3 and circulation

October 7, 2025 •

4 min read

While its counterpart, niacin (nicotinic acid), is well-known for causing a "flush" sensation by widening blood vessels, research suggests that niacinamide, a different form of vitamin B3, does not share this effect. This distinction is crucial for understanding whether niacinamide improves blood flow and its overall impact on vascular health.

Quick Summary

Niacinamide lacks the vasodilatory properties of niacin and does not directly enhance blood circulation. The evidence for its indirect vascular benefits is modest, with its main uses being skin health and metabolic support.

Key Points

Niacinamide does not cause vasodilation: Unlike niacin (nicotinic acid), niacinamide does not significantly widen blood vessels and is not used to improve blood flow directly.
No 'niacin flush' with niacinamide: The uncomfortable skin reddening and itching are caused by niacin, not niacinamide, which is why niacinamide is often preferred for treating deficiency.
Limited indirect support for circulation: Niacinamide plays a metabolic role by forming NAD+, which supports vascular health in a general sense, especially if a deficiency is present.
Primary uses are dermatological and metabolic: Niacinamide is most effective for skin health, treating conditions like acne and hyperpigmentation, and for preventing or treating pellagra.
High-dose niacin carries its own risks: Recent studies have questioned the long-term cardiovascular benefits of high-dose niacin, citing risks like glucose intolerance and potential inflammation.
Different forms have different effects: It is critical to understand that niacinamide and nicotinic acid are not interchangeable for therapeutic purposes, especially regarding cardiovascular health.

Vitamin B3, or niacin, is an essential water-soluble nutrient encompassing several forms, including nicotinic acid and niacinamide (also known as nicotinamide). Though chemically related, these forms behave very differently in the body, particularly concerning blood flow regulation. Understanding these differences is key to separating fact from fiction regarding the cardiovascular effects of niacinamide.

The crucial distinction between niacinamide and niacin

The primary reason niacinamide does not improve blood flow in the same way as niacin is its lack of a vasodilatory effect. Vasodilation is the widening of blood vessels, which can improve circulation. It is caused by niacin (nicotinic acid) binding to a specific receptor (GPR109A) in the skin, which triggers the release of prostaglandins. This biological cascade leads to the well-known niacin flush—a temporary reddening, warming, or itching of the skin.

Niacinamide, on the other hand, does not activate this receptor and therefore does not cause flushing or significant vasodilation. For this reason, high-dose niacinamide is often preferred for treating pellagra (severe vitamin B3 deficiency) over niacin because it avoids the uncomfortable flushing side effect. This fundamental difference in mechanism means niacinamide is not used therapeutically to induce vasodilation or directly improve circulation.

Can niacinamide support circulation indirectly?

While niacinamide lacks a direct impact on blood vessel width, some scientific rationale exists for its modest, indirect role in supporting vascular health, largely extrapolated from studies on niacin.

Support for metabolic function: Both niacinamide and niacin serve as precursors for essential coenzymes like NAD+ and NADP+, which are critical for cellular metabolism and energy production. These coenzymes play a role in maintaining overall vascular health, especially in cases of deficiency.
Antioxidant and anti-inflammatory properties: Some research on niacin has identified antioxidant and anti-inflammatory effects that are independent of its lipid-lowering capabilities. While evidence for niacinamide is weaker in this regard, it contributes to the overall body of knowledge about vitamin B3's benefits for endothelial function, the health of the cells lining blood vessels.
Correcting deficiency: In severe deficiency states like pellagra, where vitamin B3 levels are critically low, normal vascular function can be impaired. Supplementing with niacinamide can resolve these deficiency-related vascular issues, indirectly supporting circulation by restoring overall health.

It is important to emphasize that these potential indirect benefits are not a substitute for the pharmacological effects of prescription niacin used for cardiovascular conditions. The scientific evidence for using niacinamide specifically for improving circulation is limited.

The evolving view on high-dose niacin for heart health

Historically, high-dose niacin (nicotinic acid) was used to manage cholesterol levels and reduce cardiovascular risk. However, more recent large-scale clinical trials have questioned its long-term efficacy when added to modern, effective statin therapy. Concerns have also emerged regarding potential adverse effects associated with high doses, such as increased diabetes risk and vascular inflammation caused by certain niacin metabolites. This evolving evidence further underscores that vitamin B3's role in cardiovascular health is complex and varies significantly between its different forms and dosages. It is a field best navigated with guidance from a healthcare professional.

Comparison of Niacin and Niacinamide Effects


Feature	Niacin (Nicotinic Acid)	Niacinamide (Nicotinamide)
Effect on Blood Vessels	Causes significant vasodilation (widening of blood vessels).	Does not cause significant vasodilation.
Flushing Side Effect	Yes, commonly causes skin flushing, redness, and itching.	No, does not cause the typical "niacin flush".
Impact on Blood Flow	Directly improves blood flow via vasodilation, especially in cutaneous (skin) vessels at high doses.	No direct impact. Only minor, indirect support by correcting deficiency.
Cholesterol Effects	Raises HDL ("good") cholesterol and lowers LDL ("bad") cholesterol and triglycerides at high doses.	Does not have significant cholesterol-altering effects.
Primary Therapeutic Uses	Historically used for dyslipidemia (cholesterol issues); treats pellagra.	Treats pellagra; widely used in skin care products.
Common Side Effects	Flushing, itching, gastrointestinal issues, potential liver toxicity at very high doses.	Generally well-tolerated. Rare side effects include upset stomach or potential low platelet count at very high doses.

Dietary sources of vitamin B3

For most people, a balanced diet provides sufficient vitamin B3 to meet daily requirements. The body can also synthesize niacinamide from the amino acid tryptophan, found in protein-rich foods. Good food sources of vitamin B3 (in its various forms) include:

Meat and Fish: Poultry (chicken, turkey), beef liver, salmon, tuna.
Legumes and Nuts: Peanuts, sunflower seeds.
Grains and Cereals: Brown rice, whole-grain cereals.
Vegetables: Mushrooms, green peas, potatoes.

Conclusion

In summary, the notion that niacinamide improves blood flow is generally inaccurate. The powerful vasodilatory effects and blood flow enhancement associated with vitamin B3 are specific to the nicotinic acid form (niacin). Niacinamide, while an essential nutrient for cellular metabolism and beneficial for skin health, does not cause significant vasodilation and is not a treatment for poor circulation. For individuals concerned about their blood flow, it is far more effective to focus on proven strategies such as regular exercise, a balanced diet, and, if needed, medical treatments prescribed by a healthcare provider. Confusing these distinct forms of vitamin B3 could lead to ineffective self-treatment. Always consult a medical professional before taking new supplements or if you have concerns about circulation. You can find additional reputable information at authoritative sources like the Mayo Clinic's guidance on niacin and its uses.

Frequently Asked Questions

The main difference is their effect on blood vessels and cholesterol. Niacin (nicotinic acid) causes vasodilation and can affect lipid profiles at high doses. Niacinamide does not cause vasodilation or affect cholesterol levels significantly.

Yes, if you are addressing a vitamin B3 deficiency (pellagra), niacinamide is often used because it provides the essential nutrient without causing the skin flush associated with niacin. However, niacinamide is not a substitute for niacin in treating high cholesterol.

No, niacinamide is not effective for directly improving circulation issues like peripheral vascular disease. The evidence for its specific use in this area is limited, and the vasodilatory effects are minimal compared to niacin.

People use niacinamide for its benefits related to skin health, such as reducing acne, improving skin texture, and minimizing fine lines. It is also used to prevent or treat niacin deficiency (pellagra).

While generally safe, very high doses of niacinamide (over 3 grams per day) can cause side effects like nausea, diarrhea, and, in rare cases, liver toxicity or low platelet counts. High doses should be taken only under medical supervision.

You should consult a healthcare professional. They can properly diagnose the cause of your concerns and recommend effective, scientifically-backed treatments and lifestyle changes, such as regular exercise and a heart-healthy diet.

A balanced diet provides sufficient vitamin B3. Good sources include fish (tuna, salmon), poultry, beef liver, whole grains, nuts, and legumes. The body can also produce niacinamide from the amino acid tryptophan, found in many protein-rich foods.