The 6 Best Weight Loss Supplements for Men

If you’ve wandered down a drugstore aisle recently, you’ve no doubt seen men’s weight loss supplements promising to boost metabolism, curb cravings, banish bloating and make you a millionaire.

Okay, maybe not that last one. But the promises can get pretty wild.

These products are often touted as a way to promote weight loss, but there’s not much solid science behind them. Plus, they’re not approved by the FDA (U.S. Food and Drug Administration), so there’s no guarantee they’re safe or effective.

Sounds a bit iffy, right? Despite this, some weight loss supplements do show promise, including magnesium, caffeine, green tea, protein, fiber and vitamin B12.

Below, we’ll dive into the best weight loss supplements for men, what to look for when buying supplements and alternatives to consider.

Conjugated linoleic acid (CLA), L-carnitine, chromium, cayenne pepper — why do so many weight loss supplements begin with a C? We don’t know. What we do know is that many of them aren’t very effective for weight loss.

Some show promise, though. Here are the best weight loss supplements for men and the science behind them.

Magnesium

Magnesium is linked to everything from protein creation in the body to blood pressure and blood sugar regulation.

Magnesium deficiency can cause chronic low-grade inflammation, which could lead to a whole host of health issues, such as:

• Obesity

• Diabetes

• Cardiovascular diseases

• Depressive symptoms

• Sleep disorders

Enter: magnesium supplements. On paper, it sounds like they could help with weight loss. Here’s what the research has found.

A 2023 study measured the blood magnesium concentration of 1,000 men and women. It found that over half of the participants had suboptimal magnesium concentrations.

More worryingly? Blood magnesium was inversely associated with fat mass — that is, the lower the magnesium, the higher the fat mass.

This was especially true for those who got enough sleep and didn’t have chronic health conditions like diabetes, high blood pressure or depression.

Interestingly, there was no difference between men and women, so magnesium may be a suitable supplement for everyone.

Low magnesium levels were also associated with metabolic syndrome, which includes health issues like high blood pressure, high blood sugar and weight around the stomach.

What about magnesium supplements? Good question.

A 2020 systematic review and meta-analysis of randomized controlled trials looked at 32 studies on magnesium supplements. Doses of 48 to 450 milligrams (mg) a day over six to 24 weeks were compared.

The results showed that magnesium supplements technically led to a statistically significant reduction in BMI — or body mass index — but not a statistically significant change in body weight, waist circumference, body fat percentage or waist-to-hip ratio.

But there was a significant change in body weight and waist circumference in these subgroups:  women and participants with obesity, high blood pressure, insulin resistance-related disorders and magnesium deficiency at the start of the trial.

Pros:

• Magnesium deficiency is common and largely undiagnosed.

• Magnesium deficiency is linked to depressive symptoms and sleep disorders, two factors that can contribute to obesity. So supplements could help with weight loss in multiple ways.

• There’s some evidence magnesium supplementation could reduce BMI and reduce weight and waist circumference in those with obesity, magnesium deficiency or certain health conditions.

Cons:

• Magnesium supplements may not be as beneficial for weight loss in men and those without obesity, certain health conditions or magnesium deficiency.

Best for: Potentially people with obesity, sleep disorders, depressive symptoms, certain health conditions like diabetes and high blood pressure, or those deficient in magnesium.

Final verdict: Magnesium deficiency is linked to obesity and fat mass, and supplementation may reduce BMI, weight and waist circumference in some groups. But more research is needed.

Caffeine

Aw, coffee. Most of us can’t start our day without it. But could caffeine supplements help promote weight loss?

Well, there’s not too much solid research on caffeine supplements — sensing a theme? — but there may be a link between caffeine and weight loss.

Caffeine could help with weight loss, as it can suppress your appetite, stimulate thermogenesis (heat production) and increase fat oxidation (when your body breaks down fats). That’s why you might find caffeine advertised as an appetite suppressant for men.

Here’s the science.

A 2018 systematic review and meta-analysis of randomized controlled trials looked at 13 randomized controlled trials with a total of more than 600 participants, both male and female.

The paper concluded that “caffeine intake might promote weight, BMI and body fat reduction.”

Pros:

• There’s some evidence linking caffeine to a reduction in BMI, weight and body fat.

• Different forms of caffeine have been linked to weight loss, including yerba maté, green tea and kola nut supplements.

Cons:

• Caffeine can cause side effects, like jitters, nervousness, vomiting and tachycardia (increased heart rate).

• Too much of it too late in the day could make it hard to sleep.

• You might develop a tolerance to caffeine’s weight loss effects — just like its energy-boosting effects.

• Clinical trials are short and use a combination of products, so more research is needed.

Best for: Those who don’t experience caffeine side effects and don’t have any sleep problems.

Final verdict: Caffeine may promote weight loss, and it’s been linked to a reduction in BMI and body fat, but more research is needed.

Green Tea

Green tea is another supplement sometimes advertised as a weight loss aid, either in tea leaf form or as a concentrated supplement.

There’s some logic here.

Green tea contains caffeine and catechins (antioxidant-rich compounds), both of which may boost energy, which might lead to weight loss. The caffeine side of green tea may also suppress appetite, stimulate thermogenesis and increase fat oxidation.

Here’s what the research has found.

A 2012 meta-analysis compared randomized controlled trials on men and women with overweight or obesity that lasted at least 12 weeks.

It showed that green tea intake was linked to weight loss and a reduction in BMI and waist circumference. However, the results were small and not statistically significant.

A 2020 systematic review and meta-analysis looked at the effect of green tea supplements in those with obesity. Results showed that body weight and BMI were reduced.

Green tea intake was especially effective at reducing body weight when the dosage was less than 500 milligrams a day and participants took supplements for 12 weeks.

The researchers concluded that green tea could be combined with balanced, healthy eating and regular movement to help manage obesity.

Finally, a 2015 study found that high-dose green tea extract led to weight loss and a reduction in BMI and waist circumference in women with central obesity (around the middle of the body). More research is needed to know if green tea would have the same effect on men.

Pros:

• Green tea supplements have been linked to small amounts of weight loss

• Green tea comes with other health benefits. It has anticarcinogenic (anti-cancer), anti-inflammatory, antimicrobial and antioxidant properties and may benefit cardiovascular disease and oral health.

Cons:

• Green tea may only have a small effect on weight loss.

• Green tea supplements come with side effects like nausea, constipation, stomach discomfort and increased blood pressure. But these may be mild to moderate.

• Some green tea extracts have been linked to liver damage.

Best for: Potentially everyone or those interested in the other health benefits of green tea.

Final verdict: There’s some evidence that green tea supplements can promote weight loss and a reduction in BMI and waist circumference. But the changes may be small.

Protein

You might have heard of a low-carbohydrate or keto meal plan for weight loss. But a high-protein meal plan may be where it’s at.

That’s right, protein isn’t just for #gains. It can help with weight loss too.

Research shows that consuming more protein than the recommended amount can:

• Reduce body weight

• Decrease fat mass

• Preserve fat-free mass (i.e., muscle)

• Prevent weight gain after weight loss

Check out our guide to protein for weight loss to learn more.

You can find protein supplements in powders, shakes, gummies and bars — and they may have a place in your weight loss journey.

A 2018 systematic review and meta-analysis looked at 13 randomized controlled trials on whey protein supplementation. It found that whey protein improved body composition by increasing lean muscle mass. This may be the case for men, too, but the study only looked into women.

A small study of men from 2011 found that when participants had 20 grams of casein (a milk protein) or pea protein before a meal, they ate less than participants who had water before a meal. Compared to whey protein, casein and pea protein before a meal increased satiety — the feeling of fullness.

Protein supplementation can help with muscle growth too. A 2017 systematic review and meta-analysis looked at 49 studies on protein supplementation, which included more than 1,800 men and women.

It found that protein supplementation significantly increased strength and muscle size during resistance training. This is why protein may be one of the best supplements for weight loss and muscle gain in men.

Pros:

• #gains

• Protein may help you keep off any weight you’ve lost.

• It can be hard to get enough protein from food, especially if you’re a vegetarian or vegan, so supplements can help here.

Cons:

• While there’s good evidence linking protein intake to weight loss, more research is needed on protein supplements specifically.

Best for: Those who can’t get enough protein from food sources and guys looking to preserve and build muscle or keep lost weight off.

Final verdict: High protein intake is linked to weight loss, decreased fat mass and keeping off lost weight, and protein supplementation may help you feel fuller.

Fiber

You can get fiber from fruits, veggies, nuts, beans and whole grains, as well as in supplement form.

Soluble fiber intake has been linked to increased satiety, improved blood lipid concentrations (better cholesterol levels) and better glycemic response (how your body manages blood sugar levels after eating). It’s also been linked to weight loss.

A 2017 systematic review and meta-analysis looked at how soluble fiber supplementation affected men and women with overweight and obesity. In total, 12 randomized controlled trials were included, with more than 600 participants in studies ranging from two weeks to 17 weeks.

Soluble fiber produced some promising results. Compared to a placebo, fiber supplementation reduced:

• BMI by 0.84 on average

• Body weight by almost 5.6 pounds

• Body fat by 0.41 percent on average

It also reduced fasting blood sugar levels and insulin levels.

However, we have to take these results with a pinch of salt — there were many differences among the studies, making them hard to compare.

Pros:

• It can be hard to get enough fiber from food sources, so supplements can come in handy.

• Fiber supplements may help with weight loss, as well as controlling blood sugar and insulin levels.

Cons:

• Fiber from food can help you feel fuller, but it’s unclear if supplements have the same effect.

Best for: Those who can’t get enough fiber from food sources.

Final verdict: Soluble fiber supplements have been linked to weight loss and a reduction in BMI and body fat, but more research is needed to fully confirm if they’re effective.

You might have taken vitamin C to avoid the common cold or vitamin D during long, dark winters, but vitamin supplements may also help with weight loss. Again, the key word here is may.

Here’s one more of the best men’s vitamins for weight loss: vitamin B12.

Vitamin B12

You can get vitamin B12 from food sources like meat, fish, shellfish and dairy products. But vitamin B12 deficiency is common, especially for plant-based eaters.

Vitamin B12 deficiency is also common if you take metformin for a long time. Metformin is a diabetes drug that can be prescribed off-label for weight loss — that’s when a drug is prescribed for something it’s not FDA-approved for.

Vitamin B12 deficiency has also been linked to obesity in some studies.

For example, one 2013 study looked at almost 1,000 participants, including those with overweight and obesity and a control group. Vitamin B12 was significantly lower in those with overweight and obesity compared to those with a healthy weight.

There was a significant negative correlation between vitamin B12 and BMI — that is, the lower the vitamin B12, the higher the BMI.

Still, more research is needed to find out if supplementation could help with weight loss.

A 2019 study looked at almost 3,000 participants who took folic acid (vitamin B9) and vitamin B12 or a placebo for two years.

While a higher vitamin B9 intake was linked with a lower BMI, the study couldn’t draw any solid conclusions on whether vitamins B9 and B12 combined led to BMI or body composition changes.

Supplementation can be useful for weight loss in other ways, though.

If you have a vitamin B12 deficiency, you might be hit with fatigue. And you don’t need us to tell you that everything — especially weight loss efforts — feels harder when you’re super tired. Supplementation may help by giving you an energy boost.

Pros:

• Vitamin B12 deficiency is common, so supplementation could be useful to many.

• Vitamin B12 deficiency is strongly linked with overweight, obesity and a high BMI.

• You might feel a boost in energy levels if you’re deficient, which can help you stick to healthy lifestyle changes and feel your best.

Cons:

• Vitamin B12 supplements might be better for those who have metabolic syndrome or a deficiency.

• More research is needed to know if vitamin B12 can help with weight loss.

Best for: Potentially everyone, but especially vegetarians, vegans or those who otherwise don’t get enough vitamin B12 from food sources, along with folks taking metformin or who have metabolic syndrome.

Final verdict: Vitamin B12 deficiency is common in people with overweight or obesity or those taking metformin for long periods. We offer vitamin B12 supplements as part of our comprehensive weight loss treatments to correct for this.

Buying supplements for weight loss can feel like a minefield.

Here’s what we recommend when shopping around:

• Check ingredients. Look for ingredients with some science behind them, like the ones listed above. Any products that don’t list their ingredients (or list them in a confusing way) should be approached with caution. Ideally, the labels will mention third-party testing or show certifications from trusted organizations.

• Go for reputable brands. Ignore fancy packaging and bold claims — it’s all about the brand. Go with brands you’ve heard of that have a history of producing safe supplements. Check the company’s website to see if it’s transparent about the ingredients and science behind its product.

• Check reviews. Just like when you’re hiring a plumber or booking a hotel, checking reviews is crucial. Take note of any side effects or health issues users have reported from the supplement and if there are any stories of effective weight loss.

• Avoid products that make outlandish claims. You might have seen something along the lines of “Lose all your belly fat overnight.” Ahem. Well, if a weight loss supplement promises something that sounds too good to be true, it probably is. Watch out for products touted as carb blockers, over-the-counter diet pills or metabolism boosters (or anything saying it increases your metabolic rate). Phrases like “miraculous cure,” “secret ingredient,” “scientific breakthrough” and “ancient remedy” or any product promising a no-risk, money-back guarantee should also make you think twice.

• Keep an eye on price. Alongside outlandish claims, look out for outlandishly low prices. Again, if something looks too good to be true, well…you know the rest.

• Avoid fat-burner supplements. So-called fat-burning supplements for men line the aisles of some stores. They might sound enticing but aren’t a great choice. Thermogenic fat burners claim to help you lose weight through things like increasing fat metabolism or energy expenditure and reducing fat absorption, but a 2021 study found they’re not that effective.

Our best advice? Speak with a healthcare provider. They can assess the supplement you’re considering, let you know whether it’s worth the investment and tell you if it’s safe for you to take, taking into account any health conditions you have or medications you’re on.

A healthcare provider can also test you for nutritional deficiencies and recommend supplements to target specific situations, like digestive health issues or a vegan diet. 

They can also recommend other treatments that might be more effective for weight loss and weight management.

Weight loss supplements may not be safe. This isn’t to say they’re all unsafe — it’s just that you should proceed with caution and consider speaking with a healthcare provider before taking any new supplements.

Supplements aren’t approved by the FDA, and manufacturers can often lawfully release new dietary supplements without even informing the FDA.

Some weight loss supplements are contaminated with prescription drugs or harmful chemicals. And they often contain more than one bioactive compound, which makes it tricky to predict potential risks.

Even if they’re safe, there’s limited high-quality evidence showing that weight loss supplements are effective.

Check with a healthcare provider before taking a new supplement to see if it’s safe for your overall health and well-being.

If you’re exploring weight loss options, supplements aren’t the only thing that can help.

There are FDA-approved weight loss medications, as well as medications prescribed off-label. These weight loss treatments have much more science behind them than supplements.

Weight loss injections include:

• Ozempic® and Wegovy® (semaglutide)

• Mounjaro® and Zepbound® (tirzepatide)

• Saxenda® and Victoza® (liraglutide)

Weight loss pills include:

• Topamax® (topiramate)

• Rybelsus® (semaglutide)

• Metformin

• Contrave® (naltrexone-bupropion)

• Qsymia® (phentermine-topiramate)

• Xenical® (orlistat)

Curious how some of these weight loss treatments compare? We’ve covered Ozempic versus metformin to get you started.

There are also drug-free interventions, such as nutritious eating plans, increased physical movement, hydration and getting plenty of sleep, which can help promote weight loss.

From garcinia cambogia to green coffee bean extract, there are so many weight loss supplements out there. Many come with crazy claims, and it’s easy to think they’re safe if they contain natural ingredients.

Unfortunately, they’re not always safe, and some may not be that effective.

Here’s the TL;DR on the best men’s weight loss supplements:

• Weight loss supplements aren’t approved by the FDA. That means there’s no guarantee they’re safe, effective or free from harmful ingredients. Eeek.

• Some weight loss supplements show promise. There’s some decent science behind supplements like magnesium, vitamin B12 and protein, but more research is needed overall.

• Talk to a healthcare provider before taking a new supplement. Groan, we know — but trust us on this. A healthcare professional can determine whether a supplement is safe to take, and they can recommend better (or additional) weight loss treatments if necessary.

There’s no one best fat loss supplement for men. In fact, there may not be much of a difference between the best supplements for men and women. More research is needed there too.

Even if you find a weight loss supplement that’s safe and effective, you may need additional interventions to reach your weight loss goals.

Our weight loss treatments provide a holistic approach, combining weight loss medications (if appropriate for you) with lifestyle changes and expert personalized advice. This will get you started on your weight loss journey in the safest, most effective and sustainable way possible.