Best Diet Pills 2023: Top 7 Weight Loss Supplements That Actually Work

Reviewed by Drew Sutton, MD

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Instant Knockout
Product PhenQ LeanBean Instant Knockout
Rating ⭐⭐⭐⭐⭐
5.0 stars
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  • Vegan
  • Good money-back guarantee
  • Few side effects
  • Formulated for women
  • Caffeine-free
  • Vegan, gluten-free, soy-free, non-GMO, and organic
  • Good for athletes
  • Vegan
  • FDA and GMCA registered facility

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There are a lot of diet pills on the market right now. Some of them may not even do anything. It’s hard to tell which are the best diet pills, but this list should help! Of course, it’s only a starting point, and you need to make sure to do your own research as well, but we’ve done our best to compile the good and the bad of each option, so you know exactly what to look for.

How does a diet pill work? There are a few different types of compounds found in these pills, and the brand will usually combine the effects of several to be more powerful. 

Most alter your appetite, making you feel more full with less food or decreasing your cravings. Some pills also help you lose weight by blocking you from creating fat or speeding up your metabolism so stubborn body fat burns faster. The best pills combine several of these functions.

7 Popular Weight Loss Pills & Supplements Reviewed 2023

The features we looked for in choosing these products include natural, vegan, and allergy-friendly compounds, price, levels of caffeine and other stimulants, shipping and money-back information, and third-party testing and reliability.

Best Diet Pills of 2023: Top 5 Weight Loss Supplements 2023


PhenQ is a good, affordable option that works well for most people, but people who are sensitive to caffeine or are pregnant should avoid it. 

  • Vegan
  • Good money-back guarantee
  • Few side effects
  • No synthetic additives
  • Free shipping globally
  • Not suitable for children or pregnant or nursing mothers
  • Has a large amount of caffeine

PhenQ is a very reputable and reliable weight loss pill. Their formula includes five great effects: it burns fat, blocks the production of further fat, suppresses appetite, increases energy levels, and improves your mood. Their brand is well known and has few reported complaints of side effects or contamination. The ingredients are reliable and clinically backed.

You should take two pills per day, one with breakfast and one with lunch. There is a thirty-day supply in each bottle or sixty pills. Shipping is free anywhere in the world, and there are very good discounts for buying in large quantities. Unfortunately, it does have fairly high amounts of caffeine for increased energy.


LeanBean is an excellent pill for women, and it’s also great for any kind of allergies and sensitivities. Your results with it may vary, but you can get your money back if it doesn’t work for you.

  • Formulated for women
  • Caffeine-free
  • Vegan, gluten-free, soy-free, non-GMO, and organic
  • Testing results are available online
  • 90-day money-back guarantee
  • Complicated return policy
  • Six pills each day
  • Results can be delayed and may vary

LeanBean is fantastic for any kind of sensitivity. It has no caffeine at all, which is a massive win for people with caffeine sensitivities. It’s also gluten-free, soy-free, organic, non-GMO, and vegan.

The pill’s results do vary quite a bit from person to person, although that is also true for most weight loss supplements. With their money-back guarantee, you can try it for a while before you commit (although some people have said the return process is difficult and confusing). 

You have to take a large number of the capsules – two each before breakfast, lunch, and dinner, for six total in a day. Each jar has a month’s worth of capsules, and large orders come with bulk discounts and free shipping.

Instant Knockout

Instant Knockout is a tough weight-loss pill for tough people. It’s designed for athletes and has intense concentrations of caffeine that can be a problem for people who are sensitive.

  • Good for athletes
  • Vegan
  • FDA and GMCA registered facility
  • No proprietary secret ingredients
  • Can be expensive
  • Has a high concentration of caffeine
  • Shouldn’t be taken with other supplements that contain stimulants

Instant Knockout is a serious, powerful supplement. The high concentrations of caffeine are better for men than for women, although women can also use it. The ingredients are all-natural, and it works very well as an appetite suppressant and a metabolism booster. 

One of the best features of Instant Knockout is its transparency. There are no proprietary blends or secret ingredients. Unlike some popular weight loss pills, Instant Knockout doesn’t have artificial sweeteners. The fist-shaped bottle is just a fun bonus!

It’s designed to be taken four times a day: once early in the morning and once before each meal. Be careful not to eat supper too late in the evening, or the caffeine might interfere with your sleep. 


PhenGold is all-natural and highly reliable. It’s one of the oldest supplements on the market and has proven itself through time. It works through a variety of pathways, but it does have high levels of caffeine.

  • Good money-back guarantee
  • FDA registered facility
  • Fast and reliable shipping
  • No proprietary, secret ingredients
  • High concentration of caffeine
  • Can be expensive
  • The availability is limited to certain countries

PhenGold contains no synthetic materials; all ingredients are natural. It has several effects; it suppresses appetite, encourages fat burning, and speeds up the metabolism. There are no proprietary ingredients, so you can understand what each ingredient does.

It contains a fair amount of caffeine, but not as large a dose as some of the others. It’s designed for you to take three pills each day, and each bottle is a one-month supply. PhenGold is soy-free, gluten-free, dairy-free, vegan, and non-GMO. PhenGold might not stand out of the pack, but it’s one of the most reliable brands there is and has lasted for a long time.


PrimeShred is allergy-friendly but an intense fat burner. It avoids some of the biggest problems with weight loss pills, like muscle loss and mood problems.

  • Lose weight without losing muscle
  • Backed by clinical research
  • Naturally grown, soy-free, gluten-free, non-GMO, and vegan
  • Sometimes causes upset stomachs
  • Can be expensive
  • Not safe for pregnant or breastfeeding women

PrimeShred advertises three significant effects: increasing fat-burning thermogenesis[1], speeding up metabolism, and maintaining energy and focus. It contains high-quality natural ingredients, and every ingredient is transparently listed on the label.

There have been some unpleasant side effects noted for PrimeShred, though, and it’s not safe for women who are pregnant or nursing.


Phen24 isn’t a one-size-fits-all solution; it works with your circadian rhythm in different ways during the morning and during the evening. Research supports this unique approach.

  • Clean ingredients
  • Money-back guarantee
  • Backed by clinical research
  • Works 24/7, avoiding cyclical crashes
  • Two-step process requires you to keep two bottles
  • Can be expensive

This twenty-four-hour system includes two different pills, one for the morning and one for the evening. The daytime pill, for example, increases metabolism and energy while decreasing appetite, while the nighttime pill decreases food cravings and cortisol levels to help you sleep better. 

The ingredients are clean and transparent and include vitamins and minerals to enhance your overall health in addition to the weight loss features. It’s expensive, but its ability to work with your circadian rhythm makes it worth it. It’s also worth the extra space taken up by having two bottles.


Trimtone is simple and easy, with only one dose each day. It works well, but the caffeine is a lot and can be problematic to some sensitive women.

  • Made for women
  • Suppresses the appetite
  • Only one pill a day
  • Not vegan
  • Not safe for pregnant or breastfeeding women
  • High levels of stimulants such as caffeine

Trimtone is the simplest pill on this list. With only one pill per day, it’s easy to change your habits. It works through appetite suppression, fat burning, and increasing energy and focus. 

However, it has a large amount of caffeine and other stimulants, which women can be more sensitive to than men. It’s also not vegan.

How To Choose The Best Diet Pills 

Since every person reacts differently to various compounds, the best way to choose pills is to try them and see what works. Do your research beforehand to find out what ingredients are most important, whether you want caffeine or not, whether it’s important to you that the pills be vegan, and so on. 

Then choose a brand that fits those criteria and offers a few months of guaranteed returns if you’re not satisfied, and try it out! Return it if you don’t like it, and try another until you find what works best for you.

The Most Effective Weight Loss Ingredients

Green Tea Extract

Green tea extract[2] boosts thermogenesis, especially when combined with exercise and other parts of a healthy lifestyle. In addition, it improves glucose tolerance[3] and helps oxidize away fat.


Studies have shown that caffeine can help you lose weight[4], but mostly when accompanied by exercise and a healthy diet. It aids in speeding up your metabolism, making exercise more effective.


This is a difficult-to-pronounce ingredient derived from plants that have been cultivated for medicine in China for a long time. It’s effective in large quantities when paired with a calorie-restrictive diet.

Types Of Dietary Supplements For Weight Loss

There are prescription weight loss drugs[5], which are often more effective than the over-the-counter version if your physician agrees you should use them. The alternative of natural weight loss pills can be better if you want organic compounds and try to avoid synthesized chemicals in your drugs. 

Whether you choose prescription weight loss medication or not is up to you and your preference. However, it’s worth noting that prescription weight loss pills are more likely to have adverse side effects than their natural, organic alternatives.

Dosage And Safety

Always take the recommended dose. Never ever take a higher dose than recommended; most ingredients used in natural brands are relatively safe, but the doses they’ve been studied at are the doses the manufacturers will use. Don’t take too small a dose, either, or it will likely be ineffective.

How Much Do Diet Pills Cost?

This is a difficult question to answer since it varies depending on the brand and the ingredients. However, most pills cost around $50 to $100 for a month’s supply. You get what you pay for; if you find something drastically cheaper than that, it’s likely unreliable and certainly not one of the best weight loss pills. 

Final Thought

There are a lot of different pills on the market, but we hope this guide helps you to select the best options for yourself and your lifestyle!

Frequently Asked Questions (FAQs)

Are PhenQ, PhenGold, and Phen24 related?

All three are alternatives to the brand Phentermine[6], a prescription weight loss medication. They’re not produced by the same brand or are otherwise related.

Can you take more than one diet pill?

You should definitely not do that! These pills are designed to work alone, and most of them use the same ingredients so that you could get much too high a dose.

My diet pills are making me feel sick?

Keep an eye out for adverse effects. Trouble sleeping might mean your pill has too much caffeine, and being shaky or having low energy might mean the appetite suppressant is too intense and you’re not getting enough food. Stop taking the diet pills or find a different brand if you need to.

What’s the best pill?

What’s best varies from person to person. That’s why there are so many options; which pill is best depends on whether you need it to be vegan, whether caffeine bothers you, and many other variables.

+ 6 sources

MIDSS adheres to strict procurement guidelines and relies on peer-reviewed studies, academic research institutes, and medical associations. We work mainly with peer-reviewed studies to ensure the accuracy of the information. We avoid the use of tertiary references. You can read about how we ensure the accuracy and timeliness of our content in our editorial process.

  1. Himms-Hagen, J. (1989). Role of thermogenesis in the regulation of energy balance in relation to obesity. Canadian Journal of Physiology and Pharmacology, [online] 67(4), pp.394–401. doi:10.1139/y89-063.
  2. Phung, O.J., Baker, W.L., Matthews, L.J., Lanosa, M., Thorne, A. and Coleman, C.I. (2009). Effect of green tea catechins with or without caffeine on anthropometric measures: a systematic review and meta-analysis. The American Journal of Clinical Nutrition, [online] 91(1), pp.73–81. doi:10.3945/ajcn.2009.28157.
  3. Venables, M.C., Hulston, C.J., Cox, H.R. and Jeukendrup, A.E. (2008). Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans. The American Journal of Clinical Nutrition, [online] 87(3), pp.778–784. doi:10.1093/ajcn/87.3.778.
  4. Doherty, M. and Smith, P.M. (2005). Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis. Scandinavian Journal of Medicine and Science in Sports, [online] 15(2), pp.69–78. doi:10.1111/j.1600-0838.2005.00445.x.
  5. Mayo Clinic. (2022). Pros and cons of weight-loss drugs. [online] Available at: [Accessed 13 Dec. 2022].
  6. Mayo Clinic. (2022). Phentermine weight-loss medicine: Know the side effects. [online] Available at: [Accessed 13 Dec. 2022].


Christine VanDoren, Nutritionist
Personal Trainer, Nutritionist, Health & Wellness Writer
Christine VanDoren created Edge of Longevity, an online personal training company, which helps people all over the world engage in a healthier lifestyle. After becoming an NSCA certified personal trainer and ACE nutritionist, she started spending her time training in the gym and online and creating content for Edge of Longevity, all of which is about how she has worked to better herself, and in turn, hopes to help others better themselves too. She believes the healthier one is, the happier one can be, and through Edge of Longevity, she hopes to spread that happiness to people in every country, every lifestyle, of every age and gender, and ethnicity. She warmly welcomes you to this community of people trying to make a change. In addition to sharing knowledge through her personal training and nutrition services, she enjoys writing articles and blog content over any health and wellness-related topic!


Drew Sutton, MD
Medical Writer & Editor
Drew is a retired ENT doctor who now lives in the Southeastern US. He was a member of the American Academy of Otolaryngology and a Fellow of the American College of Surgeons. He has a bachelor’s degree in Biology and Psychology and an MD degree. He completed his internship in General Surgery and Residency in Otolaryngology-Head and Neck Surgery and practiced for almost 30 years in all aspects of ENT, including a specialization in disorders of the ear and skull base. Drew is passionate about communicating his clinical experiences and making his knowledge more accessible to the general public by medical writing.

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