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6 biggest benefits of weight loss pills

Written by John Davis

Last updated: October 21, 2022

Weight loss pills are formulated specifically to boost the effectiveness of weight loss programs. These supplements work via three main pathways: boosting your body’s baseline metabolic rate, increasing the rate of fat oxidation inside your cells, and decreasing your appetite. The best weight loss pills combine all three pathways for maximal benefits.

Our research team has identified six different ways that a weight loss pill could contribute to your weight loss goals. Read on to find out more.

Weight loss pill benefits

1. Weight loss pills can help you burn more energy than you consume

Though they work through a variety of mechanisms, one thing weight loss pills have in common is tilting the calories in / calories out equation in your favor: burning more energy and suppressing your appetite to reduce your energy intake.

However you accomplish it, tilting the energy intake and expenditure equation in your favor is going to lead to weight loss.

2. Weight loss pills can speed up the rate at which you lose weight

Weight loss can be frustratingly slow. Fortunately, clinical research shows that weight loss pills (such as the FDA-approved compound Alli) can nearly double your rate of weight loss (1,2). Similar research supports the effects of other ingredients in high-quality weight loss pills, like green tea extract, conjugated linoleic acid, caffeine, and green coffee bean extract.

3. Weight loss pills don’t need to have huge effects to improve your health

Research shows that even dropping just 10% of your body mass years reduces your risk of heart disease and stroke and significantly increase your life expectancy (3,4).

4. There are several different methods that a weight loss pill can use to create weight loss

These are increasing metabolic expenditure, increasing satiety (feelings of fullness), blocking the absorption of fat or carbohydrates, and increasing fat oxidation (5). 

Many high-quality weight loss pills do several (or all) of these at once. Moreover, some weight loss pill ingredients, like green tea extract and green coffee bean extract, can work via several of these pathways at once.

Moreover, some combinations of ingredients can have synergistic effects, increasing fat oxidation while also decreasing appetite, for example.

5. A weight loss pill that blocks carbs or fat can reduce energy intake without changing your diet at all

It might seem like reducing energy intake means you have to eat less, but a carb blocker or a fat blocker can change this.

Both orlistat (a fat blocker) and white kidney bean extract (a carb blocker) are able to reduce the amount of calories you absorb from the food you eat.

6. Burning fat directly is perhaps the best way to lose weight

Weight loss pill ingredients that can achieve this include green coffee bean extract, garcinia cambogia, CLA (conjugated linoleic acid), and green tea extract.

These fat burners have been investigated in multiple studies, and several of them appear to work synergistically with caffeine (6,7,8), creating weight loss effects bigger than those you’d expect simply by adding up the effects of each ingredient separately.

Weight loss pill side effects

The different types of weight loss pill ingredients come with their own drawbacks.

Thermogenics can be dangerous when used at excessive dosages. Research published in 2022 notes that multi-ingredient thermogenic supplements modulate blood pressure, so users should be careful especially with high dosages (9).

Caffeine-containing stimulants can keep you up at night if you take them too late during the day. Caffeine’s adverse effects are well-known: jitters, anxiety, and sleeplessness (10).

These effects have to be weighed against the potent weight loss benefits of caffeine (11). If you are sensitive to caffeine, only take weight loss pills early in the day, or opt for a stimulant-free weight loss pill.

Carb and fat blockers can cause bloating and gas. A supplement that blocks carbohydrate or fat absorption can cause gastrointestinal issues, since the unabsorbed nutrients can be eaten by gut bacteria instead.

Weight loss pill dosage

One of the particular appeals of a weight loss pill is that you, the consumer, don’t have to worry about the exact dosage of each ingredient–the nutritionists and food scientists are supposed to take care of that for you. Still, here are a few guidelines to keep in mind: 

Aim for no more than 200 mg of caffeine. For most users, this is plenty to get optimal weight loss benefits from caffeine while keeping side effects in check (12).

Green tea extract: shoot for up to 800 mg total. Green tea extract contains a potent weight loss compound called EGCG; a dosage of around 400 to 800 mg of raw green tea extract gives you an effective EGCG dose (13). 

Green coffee bean extract: at least 140 mg. The upper limit of green coffee bean extract isn’t clear, but most studies use doses of at least 140 mg (14). 

Low-end weight loss pills may not have the appropriate dosage of their ingredients, but with a top-rated weight loss pill, you can just follow the recommended dosage on the bottle.

Weight loss pill benefits FAQ

Q: How do weight loss pills work?

A: To create weight loss, a weight loss pill has a few avenues of attack. 

Appetite suppressants and fiber supplements decrease your feelings of hunger, decreasing your energy intake. 

Carb blockers and fat blockers reduce the absorption of calories after you consume them, without affecting appetite.

Thermogenics work by increasing your body’s energy expenditure. Often, this involves upregulating the oxidation of fat molecules; this is what green tea extract and green coffee bean extract do.

The best weight loss pills combine these strategies to maximize weight loss.

Q: How can you get a prescription for weight loss pills?

A: Among the weight loss pills that require a prescription, the prescribing guidelines typically require that you either have (a) a BMI over 30, which makes you medically obese, or (b) have a BMI of at least 27 and have at least one health condition linked to being overweight.

This might be metabolic syndrome, type two diabetes, fatty liver disease, or other chronic health conditions. The National Heart, Lung, and Blood Institute offers a free online tool (15) to calculate your BMI from your height and weight.

If you meet one of these two requirements, you can talk with your doctor about getting a prescription for one of the prescription-only weight loss pills.

Q: Which weight loss pills are safe?

A: If you are looking for a weight loss pill with a record for safety, opt for ingredients that come from natural foods that are consumed on a regular basis.

Green tea extract is a perfect example: people drink green tea (often in quite high amounts) on a regular basis, and it only seems to be associated with health benefits, not side effects. Green coffee bean extract also seems to be quite safe, which makes sense given its roots in coffee beans.

More aggressive weight loss pills that use a lot of caffeine, or a wide range of cutting-edge herbal ingredients, may not be as safe; stick to these tried and proven weight loss supplements with a good safety record.

Q: Do weight loss pills work if you don’t exercise?

A: Most research on weight loss pills or their constituents usually tests their effects without making conscious changes to exercise routines, so the independent effect of the supplement or pill can be determined.

So, weight loss pills that use scientifically-proven ingredients do work even if you don’t change your exercise habits. However, it should not be surprising to hear that your overall weight loss results will be better if you do exercise, since your weight loss pill benefits will stack with your

Related: Our best weight loss pill picks


A weight loss pill can be the key to kick-starting your weight loss program. By upregulating your metabolism, increasing your fat oxidation, and decreasing your appetite, a weight loss pill can deliver serious results when it comes to losing weight.

These supplements not only help decrease your overall body weight, but improve your body composition, helping you shed fat while maintaining lean body mass.

Like many other supplements, weight loss pills work best when integrated into a solid diet and exercise program.


John Davis

John Davis is a Minneapolis-based health and fitness writer with over 7 years of experience researching the science of high performance athletics, long-term health, nutrition, and wellness. As a trained scientist, he digs deep into the medical, nutritional, and epidemiological literature to uncover the keys to healthy living through better nutrition.