Eat Less with Science: Top 5 Natural Appetite Suppressants and OTC Hunger Control Pills


In recent years, many people have turned to natural dietary supplements (aka “hunger pills”) to help control their appetite and manage weight. While some supplements have little to no scientific evidence supporting their claims, others have demonstrated effectiveness in suppressing appetite. In this post, we’ll look at some of the best selling appetite control pills, their ingredients and the scientific research that may or may not support the claims.

Jacked Factory “Burn-XT” Pills

Jacked Factory is a Canadian nutrition & health supplement brand established in 2014. Their “Burn-XT” pills is the #1 best selling appetite control and suppressants on Amazon, with an impressive 73,000 ratings.

Jacked Factory “Burn XT” is designed to support weight loss efforts by increasing energy, focus, and metabolic rate while suppressing appetite. It contains scientifically studied ingredients such as acetyl L-Carnitine, Green Tea Extract, Caffeine, and Cayenne Pepper Extract. It aims to assist an active lifestyle and help individuals reach their fitness goals when combined with a healthy diet and exercise plan.

*60 capsules at $34.99; 120 capsules at $54.99
All prices in the article are as of time of writing.

Burn-XT is manufactured in a cGMP facility in the USA (instead of Canada, interestingly), ensuring purity, potency, and authenticity. The supplement is not a miracle pill, but it may provide weight loss support for those who use it consistently over a period of time. Jacked Factory also offers a 30-day money-back guarantee for those who are not satisfied with the results.


IngredientsPer Capsule
Acetyl L-Carnitine HCL350mg
Green Tea Leaf Extract225mg
Caffeine Anhydrous135mg
Capsimax(R) Cayenne Pepper Fruit Extract25mg
Bioperine(R) Black Pepper Fruit Extract2.5mg

Key Benefits

  1. Appetite suppression: Some of its ingredients, particularly Acetyl L-Carnitine HCL, may help reduce feelings of hunger and cravings, making it easier to stick to a healthy diet plan.
  2. Weight loss: Burn-XT contains multiple ingredients (eg. Green Tea Extract and Cayenne Pepper Extract ) that have been clinically studied to support weight loss when used in conjunction with a healthy diet and exercise plan.
  3. Increased energy and focus: Some of its ingredients, particularly Caffeine, may increase energy levels and improve focus and concentration.
  4. Improved metabolism: Green Tea Extract, Cayenne Pepper Extract and Black Pepper Extract all contain compounds that may help boost metabolism and increase the body’s ability to burn calories.
  5. Preservation of muscle tissue: Acetyl L-Carnitine HCL can also help preserve muscle tissue by supporting healthy energy production and reducing muscle damage during exercise. This can be especially important during weight loss efforts, as losing muscle tissue can lead to a slower metabolism and make it more difficult to maintain weight loss in the long term.

How to Use

  • Start with 1 capsule, once a day with meal & water for 1 week to assess tolerance.
  • For regular use, you can take 1 capsule, twice a day with meal & water.

Scientific Research

Acetyl L-Carnitine HCL

Green Tea Leaf Extract

The main active ingredient of Green Tea Extract is EGCG (Epigallocatechin Gallate), which is a type of catechin. EGCG has strong antioxidant and anti-inflammatory properties, which may protect cells from damage, suppress the activity of pro-inflammatory chemicals, and reduce the risk of chronic diseases such as heart disease, cancer, and diabetes; EGCG may also promote weight loss, especially when taken alongside caffeine, and may improve neurological cell function and prevent degenerative brain diseases.

Green Tea
(Image: VIXI at Amazon)

In 2009, a study was conducted in the Netherlands to investigate the effects of green tea on weight loss and weight maintenance. The study involved 104 overweight or obese women and lasted for 12 weeks. The subjects were given either green tea or a placebo, and they followed a weight-loss diet. The results indicated that the consumption of green tea significantly increased weight loss and helped maintain the reduced weight [2] Trusted Website is a trusted source of scientific research, news, and reviews. Open the link → .

A meta-analysis in 2013 analyzed the effect of green tea consumption on weight loss and weight maintenance. The researchers analyzed 14 randomized controlled trials involving a total of 1,945 subjects. The results showed that green tea had a positive impact on weight loss and weight maintenance [3] Trusted Website is a trusted source of scientific research, news, and reviews. Open the link → .

Caffeine Anhydrous

Cayenne Pepper Fruit Extract

Black Pepper Fruit Extract

Potential Side Effects

  • It may cause stomach upset, nausea, vomiting, headache, and discomfort from Acetyl-L-Carnitine HCL.
  • It may cause irritability, nervousness, sleeplessness, nausea, increased blood sugar, and rapid heart beat from high Caffeine content.
  • It may cause rash, hives, or swelling from an allergic reaction.
  • You may experience jitters & restlessness as your body adjusts to the ingredients & caffeine.

HUM Skinny Bird(R)

HUM Nutrition is a California-based supplements company founded in 2012. Its Skinny Bird(R) is a dietary supplement designed to support healthy weight management by curbing appetite and supporting balanced blood sugar levels within normal ranges. The formula contains Caralluma, which helps to make you feel fuller for longer, 5-HTP to balance mood and control stress eating, and Chromium for blood sugar support and reduced cravings.

The supplement is made with clinically proven nutrients and verified clean ingredients, free of artificial colors, sweeteners, flavors, and preservatives.


IngredientsPer Serving
Caralluma fimbriata extract333mg
5-HTP (from Griffonia simplicifolia, seed)100mg
Green tea extract (leaf, 50% caffeine)66mg

Key Benefits

  • Helps curb appetite
  • Supports healthy blood sugar levels already within normal ranges
  • Helps reduce stress eating

Scientific Research

Caralluma Fimbriata Extract

Caralluma Fimbriata Extract is made from a popular edible cactus in India. It’s believed to have appetite-suppressing and weight loss properties.

Caralluma plant
(Image: JAGREX at Amazon India)

In a 12-week trial in Australia, 33 overweight or obese adults were randomly assigned to either receive Caralluma Fimbriata Extract or a placebo while following a reduced-calorie diet and exercise plan. The group taking Caralluma experienced a decrease in appetite of food and sodium intake, and had a greater decrease in waist circumference and waist-to-hip ratio compared to the placebo group [7] Trusted Website is a trusted database of scientific and medical publications. Open the link → .

A 2006 study investigated the effect of Caralluma Fimbriata Extract on appetite and food intake in overweight Indian adults. Fifty men and women with a BMI over 25 kg/m2 were randomly assigned to either receive a daily dose of Caralluma extract or a placebo for 60 days, while following a weight-reducing diet and physical activity guidelines. At the end of the study, the experimental group showed a significant decline in waist circumference and hunger levels compared to the placebo group, suggesting that Caralluma extract may help suppress appetite and reduce weight [8] Trusted Website is a trusted database of scientific and medical publications. Open the link → .



Green Tea Extract

NatureWise Pure Garcinia Cambogia

NatureWise is a California-based supplement company founded in 2012. Its Pure Garcinia Cambogia is a natural weight loss supplement that supports metabolism and appetite management. The potent extract is derived from the rind of the Garcinia Cambogia fruit and contains 60% Hydroxycitric acid (HCA), the active ingredient that has been clinically shown to block excess carbs and sugars from being stored as fat and increase serotonin levels, which can help reduce emotional food cravings.

NatureWise’s Garcinia Cambogia is plant-based, non-stimulating, and free from artificial additives or fillers. The product is third-party tested for purity, ensuring the highest quality and efficacy.


IngredientsPer Capsule
Garcinia Cambogia Extract (60% HCA)500mg
Total Hydroxycitric Acid 300mg

Scientific Research

Garcinia Cambogia is a tropical fruit that is native to Southeast Asia and India. It contains a compound called hydroxycitric acid (HCA), which is believed to have several health benefits, including weight loss control, lowering cholesterol, regulating blood sugar and anti-inflammatory effects.

Garcinia Cambogia fruit
(Image: Vssun at ml.wikipedia)

In a 2010 meta-analysis published on the Journal of Obesity, researchers reviewed 23 randomized clinical trials, with 12 meeting the criteria for inclusion, and 9 providing data suitable for statistical pooling. The analysis revealed a small but statistically significant difference in weight loss favoring HCA over a placebo. However, the study also concludes that the magnitude of the effect is small, the clinical relevance is uncertain, and that future trials should be more rigorous and better reported [12] Trusted Website PubMed is a data base from US National Institutes of Health. It’s a trusted source of health and medical information. Open the link → .

How to Use

  • Standard serving: Adults take 1 capsule, three times daily, 30 minutes to 2 hours before meals, with a full glass of water.
  • Maximum serving: Adults take 3 capsule, three times daily, 30 minutes to 2 hours before meals, with a full glass of water.

Potential Side Effects

  • Cases of liver damage associated with the use of garcinia cambogia products have been reported. This problem appears to be uncommon, but some cases were severe. Most of the reported cases involved products labeled as containing a combination of ingredients, but some involved products labeled as containing only garcinia cambogia[13] Trusted Website U.S. National Center for Complementary and Integrative Health Open the link → .
  • Other side effects associated with garcinia cambogia include headache and nausea, diarrhea, and other gastrointestinal symptoms.
  • Little is known about whether it’s safe to use garcinia cambogia during pregnancy or while breastfeeding.

Relora™ (for Stress Caused Overeat)

The stress hormone, called cortisol, can cause an increase in appetite, leading people to overeat. A 2018 study in Turkey involving 107 students between 19 and 23 years found that the mean cortisol level increased approximately 9 times in stressful periods compared with that in relaxed periods [14] Trusted Website NCBI, US National Center for Biotechnology Information, is a trusted source of biotechnology and biomedicine information. Open the link → .

Relora™ is a blend of plant extracts from Magnolia officinalis and Phellodendron amurense, which supports healthy cortisol levels within the normal range and helps manage weight by controlling stress-related eating and appetite. It is a non-sedating supplement that has been clinically validated to support the body’s response to minor, temporary stress, which can result in nervous tension, irritability, fatigue, sadness, and nervous eating.

NOW Supplements’ Relora™ pills are kosher, soy-free, vegan/vegetarian, egg-free, dairy-free, and made without gluten, and is packaged in the USA. NOW Supplements is a family owned business since 1968 and is based in Illinois.


IngredientsPer Serving

How to Use

Take 1 capsule, 2 to 3 times daily.

Scientific Research

In a 2006 study, 28 women between the ages of 20 and 50, who typically ate more when stressed, were given either Magnolia and Phellodendron extract or a placebo three times a day for six weeks. Results showed that those taking the supplement did not experience significant weight gain, while those taking the placebo did. The supplement was also found to lower cortisol levels, which are associated with stress, in the treatment group [15] Trusted Website PubMed is a data base from US National Institutes of Health. It’s a trusted source of health and medical information. Open the link → .

In a 2013 study, 56 people (35 men and 21 women) were either given Relora or a placebo for 4 weeks. Results showed that the group taking Relora had significantly lower cortisol exposure and improved mood parameters, including less stress, tension, depression, anger, fatigue, and confusion, and higher global mood state and vigor [16] Trusted Website NCBI, US National Center for Biotechnology Information, is a trusted source of biotechnology and biomedicine information. Open the link → .

Potential Side Effects

No known side effects are listed. The manufacture cautioned that it is for adults only; do not take if you’re pregnant of nursing.

Transparent Labs “Fat Burner” Pills

Transparent Labs is an Utah-based supplements company founded in 2015. Its PhysiqueSeries “Fat Burner” is an all-natural dietary supplement designed to help you expedite weight loss by controlling cravings, boosting metabolism, and facilitating lipolysis and fatty acid oxidation. It contains a blend of ingredients that have been scientifically proven to increase fat burning, suppress appetite, and improve mood, such as Green Tea Extract, Caffeine, Forskolin, 5-HTP, L-Tyrosine, L-Theanine, cayenne pepper extract. However, caution has been noted about Synephrine.

Key Benefits

  • All-natural ingredients
  • Suppresses appetite and burns fat at the same time
  • Facilitates lipolysis and fatty acid oxidation for efficient fat burning
  • Increases metabolism
  • Helps maintain muscle mass while losing body fat
  • Promotes a healthy mood and enhances focus
  • Suitable for an enjoyable weight loss lifestyle
  • Third-party tested for purity, potency, and authenticity


IngredientsPer serving
Forslean (10% forskolin)500mg
Green Tea (50% EGCG)400mg
Caffeine Anhydrous240mg
Salicin (White Willow) Bark120mg
Cayenne Pepper Extract100mg
Synephrine HCl50mg

How to Use

  • Take 2 capsules with 8-10 ounces of water, twice daily, 30-60 minutes before meals.
  • Start with 1 capsule, twice daily, to assess tolerance for the first 3 days, then gradually increase dosage.
  • Never consume more than 2 capsules in a 4-hour period and/or consume more than 4 capsules in a 24-hour period. Do not take it within 4 hours of bedtime.

Scientific Research

Forslean (Forskolin)

Forslean is an extract from the roots of the Coleus forskohlii plant. Its active ingredient is called forskolin. Coleus forskohlii is a plant from the mint family that grows in tropical regions of Asia, such as Nepal, India, and Thailand.

Coleus forskohlii sold on Amazon India

In a study published in the journal Obesity Research in 2005, researchers investigated the effects of a forskolin-containing supplement on body composition and appetite in overweight and obese men. The study found that after 12 weeks of supplementation, the participants had significant reductions in body weight and body fat percentage, as well as decreased hunger and increased feelings of fullness [17] Trusted Website is a U.S. publishing company that specializes in academic content with 200 years of history. Open the link → .

Green Tea Extract (EGCG)


Caffeine Anhydrous

Cayenne Pepper Extract

Salicin (White Willow) Bark



Synephrine HCl

Potential Side Effects

The product contains caffeine and synephrine HCl, which are stimulants and may cause side effects such as jitteriness, anxiety, and difficulty sleeping. Additionally, cayenne pepper may affect people with a sensitivity to nightshades. People with caffeine sensitivity or autoimmune conditions should consult with a healthcare professional before taking this supplement.

Medication for Appetite & Weight Control

Prescription appetite suppressants can be effective when combined with a healthy diet and exercise, leading to a weight loss of 3% to 9% of the starting weight within 12 months. Some people may benefit from using appetite suppressants as a jumpstart to weight loss and to learn to recognize cues that signal when they are full.

It is important to note that using appetite suppressants should not be the sole method of weight loss and should be combined with lifestyle changes for best results. Also, appetite suppressants can have side effects and are not recommended for everyone, including those with certain medical conditions or who are pregnant or breastfeeding.

The Food and Drug Administration (FDA) has approved these prescription appetite suppressants:

  • Diethylpropion (Tenuate dospan(R)).
  • Liraglutide (Saxenda(R)).
  • Naltrexone-bupropion (Contrave(R)).
  • Phendimetrazine (Prelu-2(R)).
  • Phentermine (Pro-Fast(R)).
  • Phentermine/topiramate (Qsymia(R)).

If your ultimate goal is to lose weight and keep fit, Alli(R) is a widely used over-the-counter weight loss aid developed by GlaxoSmithKline. It is the only FDA-approved non-prescription weight loss product available in the United States. Its active ingredient, orlistat, has been clinically proven to help individuals lose weight effectively and safely.

Alli works by blocking the absorption of dietary fats in the body, which in turn reduces the number of calories consumed. The main component, orlistat, inhibits the action of lipase enzymes in the gastrointestinal tract, preventing the breakdown and absorption of fat from food. As a result, the unabsorbed fat is excreted through the digestive system, leading to weight loss [19] Trusted Website PubMed is a data base from US National Institutes of Health. It’s a trusted source of health and medical information. Open the link → .

alli Weight Loss Diet Pills, Orlistat 60 mg Capsules, Non Prescription Weight Loss Aid, 120 Count Refill Pack
24,977 Reviews
alli Weight Loss Diet Pills, 120 capsules

The FDA approved Alli for over-the-counter use in 2007. Customer reviews of Alli have been generally positive, with many users experiencing significant weight loss over time. Alongside a reduced-calorie, low-fat diet and regular exercise, Alli has helped countless people reach their weight loss goals. However, it is essential to note that results may vary, and some users may experience side effects, such as gastrointestinal discomfort.

19 references

[1]. Talenezhad N, et al. Effects of l-carnitine supplementation on weight loss and body composition: A systematic review and meta-analysis of 37 randomized controlled clinical trials with dose-response analysis. Clinical Nutrition ESPEN. 2020 30053-X/fulltext )

[2]. Hursel R, et al. The effects of green tea on weight loss and weight maintenance: a meta-analysis. International Journal of Obesity. 2010

[3]. Huang J, et al. The anti-obesity effects of green tea in human intervention and basic molecular studies. European Journal of Clinical Nutrition. 2013

[4]. Hursel R, et al. The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis. Obesity Reviews. 2011

[5]. Whiting S, et al. Capsaicinoids and capsinoids: A potential role for weight management? A systematic review of the evidence. Appetite. 2012

[6]. He J, et al. Effect of piperine on the mitigation of obesity associated with gut microbiota alteration. Current Research in Food Science. 2022

[7]. Astell KJ, et al. A pilot study investigating the effect of Caralluma fimbriata extract on the risk factors of metabolic syndrome in overweight and obese subjects: a randomised controlled clinical trial. Complementary Therapies in Medicine. 2013

[8]. Kuriyan R, et al. Effect of Caralluma fimbriata extract on appetite, food intake and anthropometry in adult Indian men and women. Appetite. 2007

[9]. Kobla HV, et al. Chromium, exercise, and body composition. Critical Reviews in Food Science and Nutrition. 2000

[10]. Ceci F, et al. The effects of oral 5-hydroxytryptophan administration on feeding behavior in obese adult female subjects. Journal of Neural Transmission. 1989

[11]. Cangiano C, et al. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. International Journal of Obesity and Related Metabolic Disorders. 1998

[12]. Onakpoya I, et al. The Use of Garcinia Extract (Hydroxycitric Acid) as a Weight loss Supplement: A Systematic Review and Meta-Analysis of Randomised Clinical Trials. Journal of Obesity. 2010

[13]. National Center for Complementary and Integrative Health, Garcinia Cambogia. 2020

[14]. Cay M, et al. Effect of increase in cortisol level due to stress in healthy young individuals on dynamic and static balance scores. Northern Clinics Of Istanbul. 2018

[15]. Garrison R, et al. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med. 2006

[16]. Talbott SM, et al. Effect of Magnolia officinalis and Phellodendron amurense (Relora(R)) on cortisol and psychological mood state in moderately stressed subjects. The Journal of the International Society of Sports Nutrition. 2013

[17]. Godard MP, et al. Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men. Obesity Research. 2005

[18]. Operation Supplement Safety, Department of Defense. Synephrine in Dietary Supplement Products. 2022

[19]. Rucker D, Padwal R, Li SK, Curioni C, Lau DC. Long term pharmacotherapy for obesity and overweight: updated meta-analysis. BMJ. 2007 Dec 8;335(7631):1194-9. doi: 10.1136/bmj.39385.413113.25. Epub 2007 Nov 15. Erratum in: BMJ. 2007 Nov 24;335(7629). doi: 10.1136/bmj.39406.519132.AD. PMID: 18006966; PMCID: PMC2128668.

Derek Yang

I'm an immigrant living with my family in a small town on the East Coast. I love classical music, enjoy a good cup of coffee, and have a soft spot for BMWs. I believe in lifelong learning and look forward to connecting with you to share our life experiences. Twitter @mrderekyang.

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