Supplements

Can an NAC Supplement Zap Cravings & Make Weight Loss Easier?

Written by Kat Kennedy, NASM CPT, NCSF CPT, NCSF SNS
Medically Reviewed by Dr. Elaine Gavalas, ND, PhD

Updated on September 13, 2024

If you’re trying to lose weight, you’re not alone. In fact, almost half of American adults have tried to lose weight in the past year (1). Sustainable weight loss can feel challenging and often unattainable.

But don’t lose hope yet. 

Weight loss comes down to developing long-term healthy habits like eating right and exercising. But sometimes, your body does need a little help. 

While there is no magic pill that will instantly shed those unwanted pounds (despite what some companies try to tell you), new scientific evidence suggests that NAC may help you maintain a healthy weight. 

Table Of Contents

What is NAC?

But first things first, what is NAC?

NAC, short for N-acetylcysteine, is a modified form of cysteine—a sulfur-rich amino acid found in high concentrations in animal proteins (eggs, meats, seafood, and dairy products) and cruciferous vegetables (broccoli, cabbage, cauliflower). NAC is important in replenishing the body's most potent antioxidant, glutathione.

It was originally introduced in 1967 as an over-the-counter medication to break down viscous mucus that can damage the lungs, pancreas, and other organs in patients with cystic fibrosis (2).

Since then, NAC supplementation has demonstrated a positive impact in the symptoms of several conditions, including (3):

  • Uncontrolled diabetes
  • Chronic inflammation from autoimmune disease
  • Cardiovascular disease (4)
  • Kidney disease
  • Cancer
  • Lung and pulmonary disease
  • Cognitive function in individuals with Alzheimer's (5)

Most recently NAC is gaining attention for another potential benefit: weight management.

Can NAC Help With Weight Loss?

The relationship between NAC and weight loss is relatively new and ever-evolving. A lot more research is needed to draw definitive conclusions, but here’s what we know so far.

Fat cell senescence (the aging of fat cells), inflammation, and insulin resistance are some of the most important mechanisms for the body’s resistance to weight loss in obese people. 

A 2023 study followed 40 obese adults who were randomly assigned to receive 600 mg of NAC or a placebo of starch powder for four weeks. The results demonstrated NAC significantly reduced signs of aging in fat cells and lowered inflammation in fat tissue compared to those in the placebo group. The NAC group also had decreased inflammation levels, blood sugar levels, insulin, and insulin resistance compared to placebo (6). 

Screenshot of an NCBI study titled "Effects of N-acetylcysteine on aging cell and obesity complications in obese adults: a randomized, double-blind clinical trial"

NAC’s Role in Metabolizing Insulin

Let’s break this down a little further…

Insulin is one of about 50 hormones circulating in the body. It plays a crucial role in regulating blood sugar levels, fat storage, and the breakdown of fats and protein (7). 

When insulin is metabolized correctly, the body can use fat for energy. Basically, when sugar goes into the blood, insulin jumps in to balance sugar levels. But if insulin isn't used right, it stays in your bloodstream. Too much insulin can sabotage weight-loss goals by signaling the body to store fat (8).

The theory is that NAC interferes with insulin's reaction with fat cells. This could help prevent your body from holding onto fat and instead release it faster from storage to burn for energy. 

NAC also works against harmful molecules in the body by reacting quickly with them and restoring our good friend glutathione. As we stated earlier, glutathione has been shown to help reduce inflammation and cell death, which could be helpful in conditions like insulin resistance (9). 

An older study from 2016 specifically compared the effects of NAC and metformin in women with polycystic ovarian syndrome (PCOS). The trial followed 94 women with PCOS for 24 weeks. The women were split into two groups, one taking NAC 600mg three times a day and the other taking 500mg oral metformin three times a day for 24 weeks (10). 

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The results showed that NAC could enhance lipid profile (the levels of different fats in your blood), fasting blood sugar, and fasting blood insulin more effectively than metformin.

However more research is needed to know how exactly NAC can help improve how the body responds to insulin.

How Does NAC Help Curb Your Cravings?

Cravings can really throw a wrench in your weight loss journey. They sneak up on you often late at night, urging you to dive into those tempting, high-calorie, low-nutrient goodies like chocolate, cake, ice cream, and pizza. If you're battling an addiction to sugar and junk food, NAC might be able to help.

So how does it work? 

Here’s the short version: in the nervous system, there’s a chemical messenger called glutamate, which carries signals from point A to point B (11). Glutamate plays a role in everything from sleep-wake cycles to an energy source for your brain, but it's especially key for learning and memory.

However, with addiction, glutamate faces a hurdle—it struggles to move in and out of brain cells as it should, causing a bit of chaos in brain function.

Enter NAC.

NAC steps in to restore one of the transporters responsible for shuttling glutamate around, thereby balancing out those brain glutamate levels. The cool part is that NAC may help to rewire the brain pathways that develop cravings (12, 13).

Some studies also suggest that NAC may help reduce the response to cues (14). Cues are things that basically remind you to crave something. For example, if you see a McDonald's commercial and start craving a Big Mac, the commercial is the cue. NAC may help break that link so that commercials no longer trigger such an intense craving.

To put it simply, NAC can help dial down cravings and teach your brain not to go all out on cravings. The result? You get better at controlling those impulses and saying no to tempting treats. This is super handy for anyone looking to lose weight by kicking the sugar or junk food habit.

Can NAC Help Your Workouts?

Weight loss isn’t just about what you eat but also how you move. And an NAC supplement may actually boost your performance in the gym, too.

May Help You Workout Longer

By preventing the buildup of free radicals in the muscle, NAC allows the sodium/potassium pump within the cells to work more efficiently and maintain a balance of these two critical electrolytes. 

The result is better stamina and delayed fatigue, allowing for greater intensity of exercise for longer periods of time. 

In a 2023 review of 16 studies, participants who supplemented with NAC showed significant improvements in exercise performance (15).

May Improve Recovery Time

Exercising creates oxidative stress, which damages muscles. NAC acts within the muscles to neutralize free radicals and relieve that stress. It delivers an increased concentration of glutathione directly into the muscle cells where we need it the most. 

This allows the muscle cells to begin the repair and regeneration process faster and more effectively. 

Basically, NAC helps your muscles repair themselves faster so you can work out harder, longer, and recover faster (15). This is especially helpful if you’re strength training and trying to build muscle.

How Much NAC Should You Take?

There is no specific dietary recommendation for cysteine because your body can produce small amounts.

But in order for your body to make cysteine, you need adequate amounts of folate, vitamin B6, and vitamin B12. These nutrients can be found in (16): 

  • Avocado
  • Spinach
  • Kale
  • Broccoli
  • Oranges
  • Bananas
  • Salmon
  • Tuna

And while most protein-rich foods—such as chicken, turkey, eggs, sunflower seeds, and legumes—contain cysteine, some people need to supplement with NAC to increase their cysteine intake (17).

NAC has low bioavailability as an oral supplement—meaning your body does not absorb it well. So the accepted daily supplement recommendation is 600–1,800 mg of NAC (18).

As always, it's best to consult your doctor or healthcare provider before starting any new supplement. They can help prescribe the best dosage for your specific health concerns.

The Bottom Line

While the relationship between NAC supplements and weight loss is relatively new, there is promising new research emerging every day.

NAC’s role in reducing inflammation, improving insulin sensitivity, and supporting liver health could make it a valuable addition to your weight management strategy. Combined with a balanced diet and regular exercise, NAC may offer extra support in achieving your health goals. As always, consult with your healthcare provider to see if incorporating NAC into your routine is a good fit for you.

Just be sure to look for an NAC supplement that is…

✓ Contains no added sugar or artificial flavoring

✓ Free of unnecessary fillers, GMOs, and common allergens like gluten, dairy, and soy

✓ Produced in a Certified Good Manufacturing Practices (cGMP) facility

✓ Made in the USA and third-party tested for purity and efficacy

Kat Kennedy
Article by

Kat Kennedy

Kat Kennedy is the Fitness and Nutrition Editor at NativePath. With a NASM CPT, NCSF CPT, and NCSF Sports Nutrition Certification, she has a passion for giving people the tools they need to feel healthy, strong, and confident.

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    Medical Disclaimer

    This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Chad Walding nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement, or lifestyle program.

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