Who Should Not Take the NMN Supplement?

December 12, 2025 •

4 min read

While NMN is generally well-tolerated by healthy adults, specific populations should exercise caution or avoid it entirely due to potential risks, medication interactions, or a lack of safety data. This includes pregnant or breastfeeding individuals, those with certain medical conditions, and those on specific medications.

Quick Summary

Certain individuals, including pregnant women, those with specific chronic conditions, and people on certain medications, should not take NMN without medical clearance. Lack of safety research in certain groups and potential interactions warrant caution.

Key Points

Pregnant or Breastfeeding Individuals: There is insufficient human research to confirm NMN's safety during pregnancy or lactation, so it should be avoided.
Pre-Existing Conditions: People with liver or kidney disease should not take NMN, as it can be improperly processed and may worsen existing issues.
Cancer Concerns: Individuals with active cancer or high risk should be cautious, as NMN's cellular effects could theoretically aid tumor growth, though evidence is inconclusive.
Drug Interactions: NMN may interfere with common medications for diabetes, blood pressure, and blood thinning, requiring medical supervision.
Allergies: Though rare, allergic reactions can occur to NMN or other supplement ingredients, necessitating immediate discontinuation.
Healthy Young Adults: Individuals under 18 or healthy young adults typically have sufficient NAD+ and are unlikely to need NMN supplementation.

Understanding NMN and Its Actions

Nicotinamide mononucleotide, or NMN, is a precursor to nicotinamide adenine dinucleotide (NAD+), a vital coenzyme found in all living cells. As humans age, NAD+ levels naturally decline, a phenomenon linked to many age-related health issues. NMN supplements are designed to boost NAD+ levels, which may support energy metabolism, DNA repair, and overall cellular function. While promising animal studies exist, human research is still emerging, and many benefits, as well as risks, are not fully understood.

Medical Conditions Requiring Caution or Avoidance

For certain health conditions, NMN supplementation is not recommended due to potential negative effects or interactions. Always consult a healthcare professional before starting any new supplement, especially with an existing medical condition.

Liver and Kidney Disease

Both the liver and kidneys are crucial for processing and eliminating supplements from the body. Individuals with pre-existing liver or kidney disease should avoid NMN. If these organs are not functioning properly, NMN or its metabolites could build up in the system, potentially worsening existing conditions or causing unpredictable side effects. While some animal studies show NMN can have protective effects on the liver, the supplement's impact on already compromised human organs is not well-studied and carries risks.

Active Cancer or High Cancer Risk

This is a highly debated and cautious area. While there is no definitive evidence that NMN causes cancer, the theoretical risk is that NMN, which boosts cellular metabolism and growth, could also fuel the growth of existing cancer cells. Some cancer cells are known to rely on NAD+ pathways for survival. For this reason, individuals with active cancer or a history of cancer are generally advised to avoid NMN supplementation unless under strict medical supervision or within a clinical trial. However, other studies suggest NMN could even be protective by enhancing immune function and DNA repair, highlighting the complexity and need for further research.

Autoimmune Disorders

Individuals with autoimmune disorders should proceed with caution. The effects of NMN on the immune system and inflammatory pathways are not fully understood, and altering these pathways could have unintended consequences for those with autoimmune conditions.

Medication Interactions to Consider

NMN can affect metabolic pathways, and some supplements may also contain additional herbal ingredients, creating a risk of drug interactions.

Diabetes Medications

NMN supplementation may influence insulin sensitivity and blood sugar levels. For individuals taking diabetes medications like insulin or metformin, taking NMN could alter how these drugs work, potentially causing blood sugar levels to drop too low. Close monitoring and medical supervision are essential.

Blood Pressure Medications

There are reports that NMN may affect blood pressure. For those on blood pressure medication, taking NMN could cause blood pressure to fall too low. It is crucial to monitor blood pressure closely and consult a doctor before combining them.

Chemotherapy Drugs

The potential for interaction between NMN and chemotherapy drugs is a major concern. NMN's effects on metabolism could interfere with the effectiveness of these treatments. Due to the serious nature of cancer treatment, individuals undergoing chemotherapy should avoid NMN unless advised by their oncologist.

Blood Thinners

As NMN might influence blood flow and vessel function, it could potentially interact with blood-thinning medications like warfarin. This risk warrants careful monitoring by a healthcare provider.

Other At-Risk Groups

Pregnant and Breastfeeding Individuals

There is a significant lack of safety data regarding NMN use during pregnancy and breastfeeding. Because NMN influences cellular function and metabolism, and its effects on fetal development or breast milk are unknown, it is strongly recommended that pregnant and nursing women avoid NMN. Instead, well-researched prenatal vitamins should be prioritized.

Children and Young Adults

NMN supplementation is generally unnecessary and not recommended for those under 18. Young, healthy individuals typically have high natural NAD+ levels, and there is no research confirming safety for children and adolescents.

Comparison Table: Groups Who Should Avoid or Use Caution with NMN


Group	Reason for Caution or Avoidance	Key Action	Authority Link
Pregnant or Breastfeeding	No human safety data; potential unknown risks to fetal development and breast milk.	Avoid. Prioritize standard prenatal vitamins.	[Healthline Article on NMN]
Chronic Liver/Kidney Disease	Impaired organ function can lead to NMN build-up or worsened conditions.	Avoid without explicit medical clearance and monitoring.	[Examine.com Safety Summary]
Active Cancer Patients	Theoretical risk of potentially fueling cancer cell growth.	Avoid. Consult oncologist before use; may be appropriate only in clinical trials.	[Omre Article on Cancer Risk]
Diabetic Patients on Meds	Potential to alter blood sugar levels and interact with medications.	Use with caution, close monitoring, and medical supervision.	[Dr.Oracle Article on Interactions]
Individuals on Blood Thinners	Possible influence on blood flow and interaction with anticoagulant drugs.	Use with caution and medical supervision.	[Longevity.Technology Article]
Young Adults (<18)	High natural NAD+ levels; no safety data for this age group.	Generally not needed. Consult a doctor for any specific concerns.	[Bowtie Article on Who Should Avoid]

Final Recommendations

Ultimately, whether to take an NMN supplement is a personal decision that should be made with a full understanding of the potential risks and limitations. For healthy, older adults, NMN appears to have a generally safe profile, but for the groups mentioned above, the risks may outweigh the unproven benefits. Transparency about your complete health history, including all medications and supplements, with your doctor is the most prudent path forward. The potential long-term effects of NMN are still under investigation, so an informed and cautious approach is best.

[Healthline Article on NMN: https://www.healthline.com/health/nmn-nicotinamide-mononucleotide-benefits-side-effects-and-dosage]

Frequently Asked Questions

You should not take NMN with blood pressure medication without consulting your doctor. NMN could potentially affect blood pressure levels, and the combination may cause your blood pressure to drop too low.

No, if you have liver disease, you should avoid taking NMN. Your liver and kidneys process supplements, and impaired function could lead to NMN building up in your system and exacerbating your condition.

No, it is not recommended for pregnant or breastfeeding women to take NMN. There is a lack of safety data and no conclusive human studies to determine its effects on fetal development or breast milk.

Individuals with a history of or active cancer should be very cautious and consult their oncologist before taking NMN. There is a theoretical concern that NMN's cellular growth effects could benefit cancer cells, even if direct evidence is inconclusive.

Yes, NMN can potentially interact with diabetes medications, as it affects insulin sensitivity and metabolism. Those on diabetes medication should not take NMN without close medical supervision and monitoring.

While NMN is generally well-tolerated, some individuals report mild side effects like nausea, headaches, or digestive discomfort. These often subside, but you should stop use and consult a doctor if they persist.

NMN is generally not recommended for young, healthy adults, especially those under 18, as their NAD+ levels are naturally high. There is no evidence of additional benefit for this group, and safety data for younger ages is limited.