If you have a liver condition, a peptic ulcer, or very low blood pressure, called hypotension, don't take large amounts of niacin. The supplement has been linked with liver damage. Liver damage can cause hypotension and might make a peptic ulcer active.
Niacin and niacinamide may make allergies worse by increasing histamine. People with low blood pressure should not take niacin or niacinamide because they may cause a dangerous drop in blood pressure.
If you take certain drugs to lower blood fats (bile acid-binding resins such as cholestyramine or colestipol), take niacinamide at least 4 to 6 hours before or after taking these medications. These products may bind with niacinamide, preventing its full absorption.
Niacinamide is generally safe to take, but not everyone needs the supplement. Besides supplements, you can find niacinamide in a variety of foods including eggs, meat, fish, milk, and vegetables.
People of all skin types can use niacinamide—from dry to oily or combination skin. To be sure it's safe, though, always apply niacinamide products to a test area of skin and observe for reactions. If you experience redness, itchiness, or further irritation, stop its use and consult a professional.
Safe but not totally for people with sensitive skin. As mentioned above, niacinamide seems to have an irritating effect when used with concentration formulas. Redness and itching are some of the common reactions. Although these are rare issues, they may still cause a great impact on someone's skin health.
DON'T MIX: AHA/BHA and niacinamide
Niacinamide is used to treat hyperpigmentation and reduce fine lines and wrinkles, while alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs) are chemical exfoliants. To understand why niacinamide shouldn't be mixed with AHAs and BHAs, you need to consider pH.
Niacinamide-containing foods or supplements are safe when taken in doses lower than 35 mg daily. Niacinamide is possibly safe when taken in doses up to 900-1500 mg daily. It might cause side effects such as stomach upset, gas, dizziness, headache, and rash.
If you have a liver condition, a peptic ulcer, or very low blood pressure, called hypotension, don't take large amounts of niacin. The supplement has been linked with liver damage. Liver damage can cause hypotension and might make a peptic ulcer active.
While rare, some people may experience an allergic reaction to niacinamide, known as contact dermatitis. Symptoms can include redness, itching, swelling, and a burning sensation. Those experiencing these symptoms should discontinue use and seek medical advice.
Ordinary niacinamide combined with an acid can cause a bad chemical reaction of redness and flushing. You'll want to leave at least 30 minutes between products or keep your niacinamide in the morning and your acids at night.
Niacinamide, a vitamin B3 derivative, is effective at reducing hyperpigmentation, capable of lightening dark spots significantly after several weeks' usage. Importantly, niacinamide is NOT a skin bleaching agent.
For general skin tone correction, a niacinamide concentration between 4-5% is often effective and well-tolerated by most individuals. For those looking to tackle more pronounced hyperpigmentation, a higher concentration of 10% may be beneficial, though it's important to monitor the skin for any signs of irritation.
Taking niacin with food may also increase niacin's bioavailability,124 whereas taking it at bedtime allows many patients to sleep through any flushing and may blunt nocturnal release of free fatty acids.
When excess niacin is broken down into 4PY, this breakdown product activates inflammatory pathways that are known to promote plaque formation in arteries. This may increase the risk of major cardiac events.
Niacinamide has been shown to ease inflammation, which can help calm redness due to conditions like acne, rosacea and eczema. It can also soothe irritation caused by strong exfoliants like retinol or glycolic acid that remove dead cells from the surface of your skin.
Niacin does have risks. It can cause liver problems, stomach ulcers, changes to glucose levels, muscle damage, low blood pressure, heart rhythm changes, and other issues. A study published in 2024 found a link between excess niacin and heart disease.
The present study also showed that nicotinamide supplementation was associated with a dose-dependent increase in oxidative tissue injury. This may account for why high doses of nicotinamide do not promote weight gain (see Fig. 7(a) and Shibata et al.
In short: Niacin is used for support for healthy cholesterol levels already within the normal range. Niacinamide is used for support for joint comfort, support for sugar balance and support for brain function, but does not support cholesterol balance.
Though all skin types can benefit from niacinamide, Dr. Li warns that "combining niacinamide with vitamin C, also known as ascorbic acid, makes niacin, and may cause skin irritation and transient flushing." For this reason, Dr.
Take for example Vitamin C and Niacinamide - two active ingredients we don't recommend using together in the same routine. The key word here is routine. You can use Niacinamide 10% + Zinc 1% in the AM routine and Ascorbyl Glucoside Solution 12% in the PM routine -- just not together in the morning or evening.
The misconception that you shouldn't use niacinamide and vitamin C together originates from outdated studies conducted in the 1960s. These early studies suggested that combining these ingredients could render them ineffective or cause skin irritation due to the instability of vitamin C in certain formulations.