Weight Loss Pills – What Are They & What Are Your Options?

With our modern, fast-paced and hectic lifestyles, it’s becoming harder and harder for us to eat healthy; as a result obesity levels have skyrocketed over the last decade. While the fundamentals of weight loss will always remain “eat less, move more”, many people still struggle to implement this advice. If you’re trying to lose weight and all diets have failed, you may be looking for a helping hand in your battle against the bulge – that’s where weight loss pills can come into play.

What Are Weight Loss Pills And How Do They Work?

The term “weight loss pill” is an all-encompassing name for either weight loss medications or weight loss supplements. They are sometimes more formally referred to as diet pills or fat burners.

The primarily purpose of weight loss drugs and weight loss supplements, as the name suggests, is to assist the user in losing weight – this is done by addressing one or more of the common causes that can usually result in weight gain.

Ways in which weight loss pills can typically work:

  • Certain weight loss pills can help reduce your appetite levels.
  • Certain weight loss pills can help reduce, or “block” the calories your body absorbs from fats and carbohydrates.
  • Certain weight loss pills may help boost your metabolic rates.

The public perception of weight loss pills can often vary significantly, with the majority of people misunderstanding their capabilities. Weight loss pills, both prescription drugs and supplements, should always be viewed as something to help support healthy weight loss (i.e. looked at as a weight loss aid) rather than being viewed as a quick fix. You will still need to stick to a nutritionally balanced, low-cal diet in order to see any results.

Depending on your current health situation, your doctor may recommend you start taking weight loss pills of some description. Based on your current lifestyle, weight and diet, you may be prescribed weight loss medications or you may be recommend an alternate over-the-counter (OTC) weight loss pill.

Which Type Of Weight Loss Pill Should I Use?

When it comes to choosing a weight loss pill, there are two main options to choose from: prescription weight loss drugs or over the counter weight loss supplements.

As a rule of thumb, prescription weight loss drugs are typically more effective than their over-the-counter cousins, however both have their pros and cons.

Option 1 – Prescription Weight Loss Drugs

There are numerous different weight loss drugs available to patents, many have been created directly for the purposes of treating obesity, while other medications are used “off-label” (i.e. used for a condition other than the original purpose of the drug) to treat weight gain. While weight loss meds can be extremely beneficial and have the ability to produce visible results, you must be the right candidate for them and you must approach using them in a realistic manner.

Firstly, prescription weight loss drugs are typically only given as a “last resort” by doctors; they are usually only prescribed when all other avenues of losing weight like dieting and exercising have consistently produced no results. Weight loss medications are often looked at as the last step before weight loss surgery.

Like most medicines, weight loss drugs can come with side effects and can be taxing on the liver – often doctors are reluctant to prescribe weight loss medications until all other avenues of weight loss have been explored. The prime candidates for weight loss drugs are those with a BMI between 28-39.

If you’re an otherwise-healthy adult, it is likely that your doctor will refer you to a specialist nutritionist, dietician or physical activity special to help you reassess your eating habits, food choices and daily exercise regime. If your doctor feels that your lifestyle and/or eating habits are not suitable for weight loss medications to be beneficial, you may not be offered them at all.

If you’re going to have success using weight loss medications, you must take the correct approach to using them.

The bottom line is, weight loss drugs essentially just make it easier for you to stick to a calorie-restricted diet. While taking the drugs you must ensure that you stick to a daily caloric-deficit (i.e. eating less calories than your body needs to sustain weight). For the average male, eating 1900-2000 calories per day will result in gradual weight loss, for the average woman the number is around 1400-1500 calories per day.

We must stress that weight loss drugs are not miracle fat burning pills. You will not be able to keep overeating and still expect to see weight loss results from the medications. Prescription weight loss drugs are not “fat burners”; they are designed to address the potential causes of weight gain so you can go on to lose weight naturally. They do not have the ability to directly and independently “burn body fat”.

As we explain in further detail later in this article, there is no weight loss pill (medication or supplement) that can counter a bad diet and lifestyle. No weight loss drug will be able to help you lose weight if you are unable to control your daily calorie intake. If you do not feel like you’ll be able to control your eating even while using the medications, you should not even consider using them.

Complete List Of Prescription-only Weight Loss Drugs

Be wary of look-alike, sound-alike supplements that attempt to mimic prescription weight loss drugs, as many of them are scams.

Option 2 – Over The Counter Weight Loss Supplements

Just as weight loss medications work in multiple different ways to cause weight loss, so too do weight loss supplements. The one big advantage of opting for supplements over medications is how quickly you’ll be able to obtain them. While you may have to jump through several different hoops to be written a prescription, you do not need a prescription or your doctors permission to start using weight loss supplements.

There are three main types of weight loss pill freely available to consumers over the counter:

Thermogenic Fat Burners / Metabolism Boosters

The first most common type of OTC weight loss pill is known as a thermogenic, or a fat burner. This type of supplement is typically formulated using caffeine, herbal extracts and various other compounds. First and foremost, a fat burner is designed to boost the user’s metabolism. The theory is that by boosting the body’s metabolic rates, the body will naturally start to burn more calories; this increased rate of caloric expenditure can help contribute towards weight loss. Unique to fat burners is their energy-boosting effects, which is normally due to their high caffeine content.

While weight loss results from fat burners are not 100% guaranteed, sustained usage can potentially lead to weight loss if used in conjunction with a calorie-restricted diet. One downside to such supplements is that users can potentially build a tolerance to the ingredients inside them, making them less effective when used over a long-term period (something that doesn’t happen with weight loss medications).

Appetite Suppressants / Hunger Busters

The second most popular type of OTC weight loss pill is known as an appetite suppressant, or a hunger buster. 

Similar to the prescription drugs, OTC appetite suppressants work to reduce the user’s desires to consume food by stopping hunger cravings. While the prescription medications typically work in a neurological manner, OTC appetite suppressants work in a much more “natural” manner by filling the stomach with expansive fiber such as Glucomannan. When consumed, the formula breaks down and swells up inside the stomach; by taking up space inside the stomach, a natural feeling of fullness is caused. The effects typically last between 2-5 hours and remain consistent no matter how long you use them for (unlike the fat burners where a tolerance can be built over time).

When used over a sustained period of time, appetite suppressants can help lower your daily caloric intake, which in turn will lead to you losing weight. It should be noted that you will need to stick to a calorie-controlled diet while using the appetite suppressants, as if you’re still overeating while using them they will likely be ineffective.

Carb Blockers / Starch Blockers

Last but by no means least, carb blockers, aka. carbohydrate inhibitors or starch blockers are the third most popular type of OTC weight loss pill.

Carb blocker pills offer users an easy means of lowering their daily caloric intake without having to make drastic diet changes. When taken before carb-heavy meals they can work to preventing starches from being absorbed by the body. The typical carb blocker will help inhibit Amylase, the enzyme responsible for breaking down starches into sugars. By blocking the Amylase enzyme, some of your consumed starch can pass through the body without being fully digested, meaning the calories are not absorbed.

While carb blockers can potentially be a very useful way of lowering your daily caloric intake, using them doesn’t give you a free pass to consume as many carbohydrates as you want without getting the calories from them, the body will still process and digest some of them.

If you are planning on using carb blockers for the purposes of weight loss, you should first assess your diet to see whether it’s worth it; if you don’t eat many carbohydrates in the first place, using a carb blocker wouldn’t really have any significant impact. If you find you are consuming enough carbohydrates to warrant using carb blocker pills, you should still ensure you stick to a calorie-restricted diet.

List Of The Most Popular OTC Weight Loss Pills

As there are literally thousands of over the counter weight loss pills to choose from, we’ve just listed the most popular ones.

Thermogenic Fat Burners:
Appetite Suppressants:
Carb blockers:

Am I Guaranteed Results Using Weight Loss Pills?

Results from both prescription weight loss drugs and OTC supplements are never guaranteed. Both are designed to either help you lower your daily calorie intake or boost your daily calorie expenditure – if you are still consuming way more calories per day than your body requires, you’re going to continue to gain weight.

The name “weight loss pill” is somewhat misleading, as it implies that the pills themselves directly and independently cause weight loss; this is not the case. The key to seeing successful weight loss results is, and always will be, a calorie-controlled diet.

There is no weight loss supplement or drug that is able to counteract a bad diet.When it comes to using weight loss pills (be it a weight loss medication or an OTC supplement), your should view them as more of a weight management pill or a weight loss aid, rather than a miracle-treatment.

Be aware that any weight lost will not be permanent.

If you do happen to see good results from using weight loss pills, you will need to ensure that you do not return to your old eating habits, otherwise the weight that you lost will likely start to return.

How Long Should I Take Weight Loss Pills For?

The length of time that you should use a weight loss pill for is typically based on a patient-by-patient basis, however the general consensus is that 12 weeks is around the average amount of time.

When used for periods shorter than 12 weeks, users run the risk of seeing poor weight loss results, however if used for periods longer than 12 weeks users can start to experience negative side effects and/or health implications.

If you are confused about how long you should be using a certain weight loss pill you should ask the advice of your doctor.

Are There Any Risks Or Dangers To Using Weight Loss Pills?

There are risks that come with using weight loss pills, both prescription and non-prescription, however, for the most part, they are safe provided they are used correctly and as directed.

If you’re prescribed weight loss medications you must ensure you following the directional advice given by your doctor. Misusing them may result in adverse reactions or negative side effects. You should absolutely not “self-medicate” or source weight loss drugs via illegitimate means – usage of such drugs must be done under medical supervision only.

Do not be tempted by lethal, black market weight loss pills such as DNP, Clenbuterol, Albuterol, T3 or EphedrineThese compounds have all been banned for good reason – they can have fatal effects.


The bottom line is there is no right or wrong choice, though sometimes weight loss pill supplements can be hit or miss depending on the formulation of that particular product. While weight loss medications are typically more consistent and effective, their downside is the potentially negative side effects and their impact on your liver when used over the long term. If you do decide to go down the weight loss drugs route, always listen to the advice of your doctor.

Marina Ma, MD
Staff Writer at DietProbe
Marina has an MD from U-M and is a resident writer and fact checker at DietProbe.