A Guide to Supplements That Support Weight Loss

If you’re researching how to lose weight, you may have found that there are a lot of products and so-called ‘fat loss supplements’ out there that claim to help. And while social media and online forums may be full of suggestions, they’re not always backed by evidence you can trust.

Whether or not you’re using prescription weight management treatments, there are many natural health products (NHPs) that may support your weight loss journey, so long as they’re used alongside a healthy diet and regular exercise. But with so many to choose from, it’s not always easy to know what works.

In this guide, our experts break down some of the more effective dietary supplements for weight loss and the science behind them, so you can make an informed decision on what might work best for you.

Article Summary:

• Supplements can be helpful in supporting a weight loss journey alongside diet and exercise, but they can’t be used as a shortcut or standalone treatment.
• Green tea extract, berberine, and psyllium are dietary supplements that may help to support weight management, though results vary from person to person.
• Some supplements may help with weight loss because of their metabolic effects or glucose management, but always choose active ingredients with evidence behind them.

How can dietary supplements help with weight loss?

There’s no magic pill that can make you lose weight without any lifestyle changes. But there are some supplements that have clinical trials to show they may provide metabolic support. That means that rather than directly burning fat, they can help with body processes involved in energy use, blood sugar control, or fat metabolism, usually in a small and indirect way.

This can all help with weight loss when combined with a healthy, calorie-deficit diet and regular physical activity. The important thing is to see them as a helpful tool to support weight management, rather than the main driver of weight loss itself.

And remember, if something sounds too good to be true, it usually is. Stick with dietary supplements and weight loss treatments that have evidence behind them to prove they work.

What to look for in weight loss supplements

Canadian weight loss supplements are regulated by Health Canada.

The good news is that Health Canada has a Licensed Natural Health Products Database, to help you find products that have been found to be safe, effective and of high quality. [1]

These include:

• Vitamin and mineral supplements
• Herb and plant-based remedies
• Traditional medicines like Traditional Chinese Medicines or Ayurvedic (Indian) Medicines
• Omega 3 and essential fatty acids
• Probiotics
• Homeopathic medicines
• Everyday products, like certain toothpastes, antiperspirants, shampoos, facial products and mouthwashes

When shopping for supplements to support weight loss, it’s important to do your research. Always make sure you:

Read the label: A good supplement will be transparent about exactly what’s inside it, listing the active ingredients, inactive ingredients and the dosage clearly.

Check the science: Look for ingredients that have clinical trials and scientific research behind them, so you don’t waste your money.

Look for licensed natural health products: Check for an eight-digit Natural Product Number (NPN) or Homeopathic Medicine Number (DIN-HM) on the label.

Science-backed supplements for weight management

The supplements that have the most evidence for helping with weight loss can generally be grouped into appetite suppressants and satiety support, metabolic boosters, and probiotics.

Here are some of the most noteworthy, from green tea and protein powders to soluble fibre and probiotics.

Berberine

Berberine is a compound extracted from several plants, including barberry and goldenseal, and is usually sold as a capsule or powder. You may have seen it described online as a natural alternative to prescription weight loss medication, but it isn't, and research doesn't support that comparison.

However, berberine may help to lower triglycerides, the most common type of fat (lipid) found in your blood. High levels of blood lipids are associated with obesity, heart disease, metabolic syndrome and type 2 diabetes or prediabetes. [2]

It’s worth noting that berberine has some common side effects, such as nausea, abdominal discomfort, constipation and diarrhea (which are all similar to the side effects associated with weight loss medication). Berberine can interfere with the liver enzymes and transport proteins that clear many common medications from your body, which can raise the levels of those medicines in your blood. This is relevant if you take, among others, hormonal contraception, blood thinners, statins, some blood pressure medicines, or immunosuppressants after a transplant. [3] [4] If you take berberine alongside diabetes medication such as metformin, your blood sugar may fall further than expected.

It should not be used in pregnancy or while breastfeeding. Berberine can displace bilirubin in the bloodstream and has been linked to a risk of jaundice and brain injury in newborns. Avoid it if you are pregnant, planning a pregnancy or breastfeeding. [5]

Caffeine

While a cup of green tea or matcha has its advantages, some specific caffeine-rich supplements have also been studied for their weight loss benefits.

Green tea extract is rich in caffeine and catechins, especially epigallocatechin gallate (EGCG). When researchers separated the two, the picture got clearer. Trials of catechins taken without caffeine showed no benefit on weight, BMI or waist size at all, which suggests the small effects seen in green tea studies come from the caffeine rather than the catechins. [6]

The evidence for the extract itself is weak. A 2021 review looked at 38 green tea trials and found only 16 were well designed. Of those 16, just two showed a meaningful weight difference, and both lasted under eight weeks. [7]

The effects of green tea extract are not guaranteed. As with all supplements, it is not a substitute for a healthy diet and regular physical activity. Moderation is also important. There may be a link between green tea extract and a risk of liver damage, even in as low a dose as 140mg per day. [8] Watch your dosage, and look out for signs of liver injury including jaundice (yellowing of the skin or the whites of the eyes), abdominal pain, pale, clay-colored stools, dark urine, fatigue, nausea or vomiting. [9]

Caffeine on its own does, however, have a small, dose-related effect. Pooled trials link higher caffeine intake to modest reductions in weight, BMI and body fat, although the studies vary widely and the effect is small. [10] You can get caffeine from coffee or ordinary tea without taking a concentrated extract. Health Canada advises healthy adults to stay under 400 mg of caffeine a day, and under 300 mg if you are pregnant, breastfeeding or planning a pregnancy. [11]

Protein

If you’re on a weight loss journey, you’ll know that one of the recommendations for your calorie-controlled diet is to prioritize protein. That’s because your body uses more energy to digest protein than carbs or fat, so it can help to increase feelings of fullness and reduce hunger between your meals. Importantly, it also helps to preserve muscle during weight loss. [12]

You can add protein to your meals, for example with chicken, fish, eggs, lentils or tofu. But if you’re finding it difficult to eat enough protein while staying within your reduced caloric intake, there are also protein powders or shakes that you can use to supplement your diet. These may help you to feel fuller through the day, as well as being a good option to replace higher-calorie foods.

The evidence is strong, too. In clinical trials, a high-protein diet has been found to help reduce body weight, preserve muscle mass and enhance body composition, and even prevent regaining weight that you’ve lost. [13]

Psyllium

Psyllium is another fibre supplement which, like glucomannan, swells when it mixes with water. This can help you to feel satisfied sooner, so you feel fuller, eat fewer calories at mealtimes, and are less likely to snack in between meals.

It's usually available as psyllium powder or psyllium husk, which uses the outer shell rather than the seed. Psyllium husk contains a higher concentration of soluble fibre.

While it can’t promote weight loss on its own, clinical trials show that taking psyllium before meals may help with weight loss in people with obesity by increasing fullness. It may also slow the absorption of glucose, which can help with appetite control and weight management too. [14]

As mentioned with glucomannan, psyllium must be taken with enough water per dose. Consuming dry psyllium or taking it with insufficient water can cause the fiber to swell in the throat or esophagus, creating a choking hazard or intestinal blockage.

Aside from dietary supplements, including plenty of fibre in your diet is also helpful for weight management. Some types of fibre can help to increase fullness, support gut hormones to reduce hunger, improve blood lipid levels, and help moderate blood sugar after meals. [15]

Probiotics

The trillions of helpful microbes living in your intestines that make up your microbiome include bacteria, viruses, fungi and yeasts. Their diversity can vary widely depending on your diet, lifestyle and even genetics. What you may not know is that an imbalanced microbiome, with an overgrowth of the more harmful bacteria, has been linked to health problems including obesity. [16]

Interestingly, research shows that people with obesity tend to have less variation in their gut bacteria, as well as different proportions of a strain that’s associated with inflammation and weight gain. [17]

There is logic to this. Your microbes help to break down food that your body can’t digest, which can have an impact on how many calories are then turned into stored fat. [18] Some bacteria also influence your hunger hormones like leptin and ghrelin. Leptin helps to signal to the brain that you’re full, while ghrelin stimulates your appetite and tells you when you’re hungry, so if they’re imbalanced it may cause you to overeat. [19]

With this in mind, keeping a healthy microbiome can be helpful when trying to lose weight. This is where probiotics supplements may be useful, though the evidence is mixed and often depends on the specific probiotic strain. Probiotics help to restore and maintain the right balance of microorganisms in your gut. [20] Probiotics may help with digestion and support a healthy gut lining, but they are not a weight loss treatment in their own right. [21]

Do vitamins help with weight loss?

Vitamins do not directly cause meaningful weight loss. However, a healthy, balanced diet is vital when you’re losing weight, and we know it’s not always easy when you’re also counting calories. That’s where vitamins and mineral supplements may help, to complement your diet with essential nutrients. Here are some to keep in mind:

Vitamin D: The sunshine vitamin is important for bone and muscle function, and it's been shown that people with obesity are more likely to have lower levels, partly because vitamin D is stored in body fat. However, clinical studies show that taking Vitamin D does not cause weight loss. [9] [22] That said, if your levels are low, correcting a deficiency is worthwhile for your bone and muscle health and may help with tiredness, so ask your healthcare provider whether testing is right for you.

B vitamins: There are 8 essential B vitamins in total: thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9), and cobalamin (B12). The body doesn't store B vitamins (with the exception of B12, which is stored in the liver). So, they need to be replenished regularly through diet or supplements to support your metabolism.

They help your body to convert carbohydrates, proteins and fats into energy, reducing fatigue and making it easier to stay physically active. [23] You can find B vitamins in meat, fish, dairy products, leafy green vegetables and beans, but if you're deficient, you may find dietary supplements helpful.

Magnesium: This mineral is important for energy production and blood sugar regulation, as well as supporting better sleep. [24] So does magnesium help with weight loss? No, not directly, but by potentially improving your sleep and energy levels, it may be a useful supplement if you are deficient. If you're doing more exercise or strength training, it can also help your muscles to relax, preventing tight cramps or stiffness. [25]

It may be worth supplementing magnesium if you know you have a deficiency, but otherwise you may get enough from a healthy, balanced diet.

Weight loss supplements that need more research

There are other supplements that claim to help with weight loss, including raspberry ketones, green coffee bean extract, apple cider vinegar and garcinia cambogia (a tropical fruit). While these have some buzz around their benefits for weight management, more research is needed to confirm how effective they are.

When to talk to a professional

If you’re considering trying dietary supplements to support your weight loss journey, talk with a health professional or your healthcare provider first. You can discuss the products’ potential benefits as well as the risks or side effects. This is especially important if you have medical conditions such as high blood pressure, diabetes, liver disease or heart disease.

Find out more about weight loss treatments and find one that’s suitable for you with MedExpress.

References

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