Last Updated: 31 July 2023

Reviewed by the BioHackers Lab Team | Last updated: July 31, 2023

Nicotinamide adenine dinucleotide (NAD) and its potential health benefits have become a hot topic in the health and wellness community. However, questions about the right dosage and how individuals respond to supplementation are still being explored. To find the best approach, follow the manufacturer’s recommendation, consider a gradual dose increase, and speak to a healthcare professional.

Man in health food store supplement aisle

Key takeaways:

  • The right NAD dosage depends on individual needs, health conditions, and the supplement’s precursor type – niacin, nicotinamide mononucleotide (NMN), tryptophan, or nicotinamide riboside (NR).
  • Niacin can be obtained through foods or supplements with an average recommended daily dose of 15 mg.
  • NMN studies show potential health benefits at doses as low as 250 mg daily with no adverse effects up to 1,250 mg per day for four weeks.
  • Tryptophan, at the recommended daily allowance (RDA) of 5 mg/kg body weight per day, is helpful for NAD production. But high doses may lead to side effects like dizziness and nausea.
  • NR studies indicate that daily doses of 1,000 to 2,000 mg are safe and effective for increasing NAD levels, but some individuals may experience mild side effects like nausea and headaches.

If you’re looking for more energy and improved well-being by increasing NAD levels, you’re in good company. But, determining the correct dosage of NAD supplements can be tricky.

Given the endorsement of NMN supplementation by advocates like Harvard researcher David Sinclair, it’s crucial to understand how to find the correct dosage for you. This article provides an overview of recommended NAD precursor dosages.

How Much NAD Should I Take?

The right amount of NAD to take depends on your needs, health conditions, and the type of precursor used in the supplement.

To meet your daily NAD needs, you can opt for dietary sources or supplements with precursors like niacin, NMN, tryptophan, or NR.

Supplements of NAD are available in various forms. Some contain only one precursor, while others may combine a few precursors with additional ingredients.


The recommended daily allowance of niacin is 16 mg of niacin equivalent for males and 14 mg of niacin equivalent for females.

A study found that taking around 15 mg of daily niacin from foods like meat, fish, and dairy products can meet your NAD needs.

Niacin can be found in multivitamin-mineral products and supplements with other B-complex vitamins. 

The two common forms of niacin in supplements are nicotinic acid and nicotinamide. Be cautious of niacin-only supplements containing 500 mg or more in one serving. This amount is significantly higher than the RDA.

Nicotinamide Mononucleotide (NMN)

Some studies suggest that taking as little as 250 mg of NMN daily may offer potential health benefits in healthy older men. Other research has explored higher doses, reaching up to 1,250 mg daily for four weeks, with no significant adverse effects reported.

A different study found that when combining exercise with NMN supplementation, the aerobic advantages depended on the NMN dose, and 1200 mg of NMN had a better effect. Surprisingly, in the same study, the 600 mg/day NMN dose – rather than the higher 1200 mg/day dose – had a positive impact on other physical functions.

Despite these encouraging findings, further research is required to fully understand the effects of NMN at different dosage levels.


The US RDA for tryptophan is 5 mg per kilogram of body weight per day. For someone weighing 150 pounds (around 68 kilograms), taking 5 mg of tryptophan per kilogram of body weight would be about 340 mg of tryptophan.

Tryptophan is an essential amino acid that our bodies use to produce NAD. It’s found in various foods, both from plant and animal sources.

Nicotinamide Riboside (NR)

Research studies have demonstrated the safety and effectiveness of NR supplements in raising NAD levels. The recommended NR dose ranges from 300 mg to 2000 mg per day.

In a study, older, slightly overweight, but healthy men were given 1000 mg of NR daily for 21 days, and it was well tolerated with no harmful effects.

Another study found that taking 1000 mg of NR daily is safe and effective for boosting NAD levels in healthy middle-aged and older individuals.

If you’re considering starting NAD supplements, speak to a healthcare professional who can assess your health needs and guide you on the appropriate dosage recommendation. 

Additionally, paying attention to your body’s response and being mindful of any changes or side effects while taking NAD supplements can help determine if the dosage suits you.

What Are the Side Effects of NAD?

NAD is a molecule that naturally occurs in the body and generally produces no side effects. However, NAD supplements and some dietary sources of NAD can cause side effects. These side effects vary depending on the type of NAD precursor used.

Let’s look at the reported side effects of various NAD precursors:


When taken in high amounts, nicotinic acid (a component of niacin) supplements can cause skin flushing. To minimize this, some formulations are labeled as prolonged, sustained, extended, or timed-release.

Taking high doses of nicotinic acid over a long time may harm the liver, causing issues like increased liver enzymes, tiredness, nausea, and loss of appetite. In some cases, it can lead to hepatitis or liver failure. The risk of liver problems is higher with extended-release forms of nicotinic acid.

Taking approximately 3,000 mg of nicotinamide (another component of niacin) per day can lead to nausea, vomiting, and signs of liver toxicity. When healthy individuals consumed nicotinamide in doses of up to 6000 mg on an empty stomach, they experienced side effects such as headaches, dizziness, and vomiting.

Nicotinamide Mononucleotide (NMN)

In studies involving rodents, NMN is well tolerated without any significant toxicity or serious side effects. A single dose ranging from 100 to 500 mg of NMN in healthy adults did not result in any noticeable side effects.

An additional study has investigated higher doses of NMN, as much as 1,250 mg daily for four weeks, and found no noteworthy adverse effects.

NOTE: As of the fall of 2022, NMN is under investigation by the FDA as a potential new drug. As a result, the FDA ruled that the legality of NMN as a dietary supplement is uncertain and may be subject to change.


While tryptophan is generally considered safe when consumed in average dietary amounts, taking high doses of tryptophan in supplement form may lead to some side effects.

Dizziness, drowsiness, dry mouth, headache, loss of appetite, and nausea are common side effects of tryptophan supplements.

Nicotinamide Riboside (NR)

In research involving humans, using daily doses of 1,000 to 2,000 mg of NR did not show any harmful effects. Studies conducted in humans and mice showed no serious side effects from NR supplementation.

However, in a study, a few individuals mentioned experiencing nausea, fatigue, headaches, diarrhea, stomach discomfort, and indigestion when taking a combination of NR and pterostilbene.

Participants of a different study taking 1000 mg of NR daily noted some side effects, including nausea, flushing, leg cramps, and increased bruising.

More extensive human studies are required to better understand NR’s safety.

How Should I Take NAD?  

When it comes to supplementing with NAD, it’s best to follow the manufacturer’s instructions and guidelines. Each NAD supplement may have specific precursors at different doses and recommended usage. Read the label carefully and adhere to the provided instructions.

Speaking to a healthcare provider is highly recommended before starting a new NAD supplementation regimen. They can assess your individual health needs, medical history, and any potential interactions with other medications you might be taking.

Also, starting with a small dose and gradually increasing it is prudent. This allows your body to adjust to the supplement and helps you monitor potential side effects or adverse reactions.

Remember that NAD supplements are not intended to replace healthy lifestyle practices. They are meant to complement and support your overall well-being. Alongside taking NAD supplements, aim to maintain a balanced diet, engage in regular physical activity, and get enough restful sleep for optimal health.


What does NAD do?

NAD plays a vital role in our cells by helping convert food into energy, supporting various bodily functions, and DNA repair.

What are the benefits of NAD?

In addition to increasing energy, NAD can potentially slow down aging, aid cognitive function, and help prevent cancer.

Can I obtain NAD through food?

NAD itself isn’t directly present in food, but certain foods contain compounds known as NAD precursors that support our body’s NAD production.

How do I boost my NAD level?

To boost your NAD levels, try including foods rich in NAD precursors like meat, broccoli, and fish in your diet. Leading a healthy lifestyle with regular exercise and proper sleep can also help.

If you consider NAD supplements, follow the manufacturer’s directions and speak to a healthcare professional to ensure safe use. 

How often should I take NAD? 

How often you should take NAD depends on the supplement type and your personal requirements. Follow the manufacturer’s recommendations.

How can I tell if NAD supplements are working? 

You may test your NAD levels to see if your NAD supplements are working. Observing improvements in energy and overall well-being can also indicate its effectiveness. Consulting a healthcare professional can provide valuable guidance.

Final Thoughts

Your healthcare provider is your best ally when it comes to NAD supplements. Follow the manufacturer’s recommendations, as the dose may vary depending on the NAD precursor(s) included in the supplement. It’s also a good idea to start with a small dose and slowly increase it. Everyone is different, so gradually building tolerance can help you adjust to the supplement.

Maggie Aime RN

Maggie Aime, MSN, RN

Maggie Aime, MSN, RN is a freelance health, wellness, and medical personal finance writer. Her extensive nursing experience includes oncology, kidney transplant, cardiology, and home health. Read more about her work at