Raspberry Ketone Benefits: What the Research Says

Raspberry ketone is the compound that gives red raspberries their smell, and supplements sell it in doses far above anything food provides. Cell and mouse studies suggest it can change how fat cells handle fat, but no published placebo-controlled trial has tested raspberry ketone on its own in people. The only human trials used multi-ingredient products alongside diet and exercise, so its benefits in humans remain unproven.

Key Takeaways

Raspberry ketone is an aroma compound found in small amounts in raspberries, kiwifruit, peaches and apples; most supplement raspberry ketone is made in a lab.
Supplements typically provide 100 to 1,400 mg a day. A normal diet supplies only a few milligrams.
The fat-burning idea comes from cell studies and mouse studies, not from human trials of raspberry ketone alone.
Two small human trials tested combination products that also contained caffeine and other ingredients, so the results cannot be credited to raspberry ketone.
The NIH says the safety of supplement doses has never been evaluated in humans. Read our guide to side effects to raspberry ketones before you start.

Evidence grade: Emerging. The human evidence is two small, eight-week trials of multi-ingredient products and one tiny topical study; everything else is cell or animal research.

What Is Raspberry Ketone?

Raspberry ketone, chemically 4-(4-hydroxyphenyl)-2-butanone, is the main aroma compound of red raspberries. It is used as a flavoring in foods and as a fragrance. The FDA lists it, under the name 4-(p-hydroxyphenyl)-2-butanone, among the synthetic flavoring substances permitted in food. That listing covers flavor use, not the much larger amounts sold in supplements.

The "ketone" in the name describes a chemical group in its structure. It is not the same thing as the ketone bodies your body makes on a ketogenic diet, and no study we found showed that it puts people into ketosis.

Raspberry ketone also occurs naturally in kiwifruit, peaches, grapes and apples, always in small amounts. Researchers measured up to 4.3 mg per kilogram of raspberries. At that level, a single 100 mg supplement dose would equal roughly 23 kg (about 50 pounds) of fruit.

Natural vs synthetic raspberry ketone

Extracting raspberry ketone from fruit is very expensive, so most commercial raspberry ketone is made chemically, by joining p-hydroxybenzaldehyde with acetone. The finished molecule is the same either way. There is no human research showing that "natural" raspberry ketone works differently from the synthetic form.

Where the Weight Claims Come From

The interest started with animal and cell studies. Researchers noted that raspberry ketone's structure resembles capsaicin (from chili peppers) and synephrine (from bitter orange), two compounds studied for effects on fat metabolism.

Mice, 2005: mice fed a high-fat diet containing 0.5% to 2% raspberry ketone for 10 weeks gained less body weight, liver weight and abdominal fat than mice on the same diet without it. In isolated rat fat cells, it increased fat breakdown (lipolysis) triggered by norepinephrine.
Cells, 2010: in 3T3-L1 fat cells grown in a dish, raspberry ketone increased fat breakdown, increased fatty acid burning, and raised the production and release of adiponectin, a hormone made by fat tissue that is involved in fat and glucose metabolism.
Mice, 2017: a better-controlled study added a "pair-fed" group of mice that simply ate the same reduced amount of food. Raspberry ketone lowered food intake and body weight, but it offered little benefit for fat loss beyond eating less, and it did not change blood adiponectin.

That last study matters. It suggests that at least part of the weight effect in mice came from the animals eating less. In mice, raspberry ketone is absorbed within about 15 minutes and quickly broken down, which tells us little about what happens in people.

What Human Research Measured

The NIH Office of Dietary Supplements, in its 2022 review of weight-loss ingredients, found only one randomized controlled trial of a supplement containing raspberry ketone. A second, smaller trial by the same research group was published in 2018. Neither tested raspberry ketone alone.

The 2013 trial (70 adults, 8 weeks)

Adults aged 21 to 45 with a BMI above 27 took either a placebo or a product whose 2,000 mg proprietary blend combined raspberry ketone with caffeine, bitter orange, ginger, garlic, cayenne, L-theanine and pepper extract, plus B vitamins and chromium. The dose was two capsules with breakfast and two with lunch. Everyone also ate about 500 calories a day less than they needed and exercised 60 minutes, three days a week.

Among people who finished, the product group lost an average of 1.9 kg (about 4 pounds) versus 0.4 kg on placebo, and lost more fat mass. But 25 of the 70 participants dropped out, and results were reported only for the 45 who completed the study. Two of the authors had received funding from or consulted for raw-material suppliers, and a supplement company sponsored the study. The amount of raspberry ketone in each dose was not stated in the paper's text.

The 2018 trial (36 adults, 8 weeks)

This trial tested a similar combination of raspberry ketone, capsaicin, caffeine, garlic and bitter orange, at four capsules a day, with calorie restriction and supervised exercise three times a week. Both the supplement group (18 people) and the placebo group (18 people) lost weight and body fat, which shows how much the diet and exercise program did on its own. The supplement group had larger changes in two fat-tissue hormones, leptin and adiponectin. Men in the supplement group gained lean mass, and women in the supplement group lost more from their hips.

The topical hair and skin study (2008)

The source articles we merged here mentioned hair growth. The only human data come from one 2008 study that applied a 0.01% raspberry ketone solution to the skin. Hair growth was reported in 5 of 10 people with hair loss after five months, and cheek skin elasticity improved after two weeks in 5 women. The human part of the study was very small, and the abstract does not describe a placebo comparison. It says nothing about swallowing raspberry ketone. For more on skin use, see what raspberry ketone does for skin.

Doses: What Has Been Studied

There is no established or proven dose of raspberry ketone for people. The table puts the amounts you will see in context.

Setting	Amount	What it tells us
Raspberries	Up to 4.3 mg per kg of fruit	A normal diet supplies only a few milligrams a day.
Supplement labels	100 to 1,400 mg a day	The NIH says the safety of these doses has never been evaluated in humans.
2013 human trial	4 capsules a day of a 2,000 mg multi-ingredient blend	Raspberry ketone amount not stated in the text; effect cannot be separated from caffeine and the other ingredients.
2018 human trial	4 capsules a day of a multi-ingredient product	Both groups lost weight with diet and exercise; differences were mainly in hormone markers.
2008 topical study	0.01% solution on scalp and face	Very small; applies to skin use only.
Rat safety study	No-adverse-effect level of 280 mg per kg of body weight a day	Gives a margin of safety of 165 at 100 mg a day but only 12 at 1,400 mg a day, which Danish food-safety researchers called a cause for concern.

If you do use raspberry ketone, a lower intake within the label range keeps you further from the amounts that concern toxicologists. For timing questions, see when to take raspberry ketones.

Raspberry Ketone in Combination Formulas

Most raspberry ketone products, including the ones tested in people, are combinations. OPA Raspberry Ketone Ultra provides 500 mg of raspberry ketones per two-capsule serving, with 300 mg of African mango and a 400 mg blend that includes green tea extract, caffeine anhydrous, apple cider vinegar powder, kelp and grape seed extract. It is designed to support metabolism and energy alongside balanced eating and regular movement, and it contains caffeine. Because it is a combination, the research on raspberry ketone alone does not describe it directly. You can read about one of its other ingredients in our African mango (Irvingia gabonensis) guide.

Safety and Interactions

The safety of raspberry ketone at supplement doses has never been studied in humans. The 2013 trial reported no serious adverse events and no differences in heart rate or blood pressure over eight weeks, but it was small and short. Danish food-safety researchers calculated that even a 100 mg dose is 56 times the threshold of toxicological concern used for this class of compounds, and computer models flagged possible effects on the heart and on reproduction that have not been tested.

Talk to your doctor or pharmacist before using raspberry ketone if you are pregnant or breastfeeding, have a heart rhythm or blood pressure concern, or take stimulant medicines, blood pressure medicines, blood-sugar-lowering medicines or blood thinners such as warfarin. Many products also contain caffeine, so count your total caffeine from all sources. Our full guide to side effects to raspberry ketones covers the case reports, animal toxicity data and interaction questions in detail.

Frequently Asked Questions

What does raspberry ketone do in the body?

In cell and mouse studies, raspberry ketone increased fat breakdown and fatty acid burning in fat cells and reduced food intake. Whether it does anything meaningful in people is unknown, because no published placebo-controlled trial has tested it alone in humans.

Can raspberry ketones help you lose weight?

There is no good evidence that raspberry ketone alone helps people lose weight. In the one trial the NIH reviewed, a combination product with caffeine and other ingredients, used with a reduced-calorie diet and exercise, led to about 1.5 kg more weight loss than placebo over eight weeks, with a high dropout rate. Diet and activity remain the foundation.

How much raspberry ketone should I take?

No dose has been proven effective or safe in humans. Supplement labels range from 100 to 1,400 mg a day. The common advice of 100 to 200 mg twice a day is not based on human trials. Follow the label, stay at the lower end, and talk to your healthcare provider first.

Are natural raspberry ketones better than synthetic ones?

No evidence shows a difference. The molecule is the same. Natural extraction is very expensive because fruit contains so little, which is why most supplement raspberry ketone is made chemically.

Do raspberry ketones help hair growth?

Only one small 2008 study tested this, using a 0.01% solution applied to the scalp. It reported hair growth in 5 of 10 people, without a described placebo group. That is not enough to say raspberry ketone supports hair growth, and it says nothing about capsules.

Are raspberry ketones a miracle fat burner?

No. The NIH notes that although raspberry ketone was promoted on television and online as a fat burner, little evidence supports the claim. Be skeptical of any product that promises fast fat loss.

Sources

Disclosure: OPA Nutrition sells supplements, including products mentioned in this article. This content is for education only and is not medical advice. Statements about dietary supplements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. Talk to your healthcare provider before using any supplement, especially if you take medication or have a medical condition.

Written and reviewed by Michael Gonzales, Founder, OPA Nutrition · Last reviewed: October 17, 2026 · How OPA researches and writes

Raspberry Ketones Benefits: What the Research Says

Key Takeaways