Raspberry Ketones: What Is The Evidence Beyond Dr. Oz?

Chemical structure of raspberry ketone
Image via Wikipedia

So, Dr. Oz really loves raspberry ketones.  He rhapsodizes about the ketones and compares their effect to balloons in liquid nitrogen (it would have been more impressive if he’d shattered the balloons).  At the end, we get lipservice to diet and exercise, but clearly these ketones are the trick.

Dosage?  100 mg in the morning, maybe another 100 mg at lunch.  Supposedly we see results in as little as a week.  Sign me up!

Anyone else talking about the ketones (besides the people who are selling them?)

Yep.  And the little rats love them.  At 1% of their diets, they did see some weight changes.  And Dr. Oz is right that adiponectin does alter – in mice and rats.  Where are the human studies?  Well, topically after five months a tiny number of humans had some hair regrowth.  Only about half of them.

Any human studies on weight loss?  Nope.  But we’ll be seeing the raspberry ketone diet craze sweep the nation anyway.

The problem is that this isn’t a nice little raspberry spray.  The fact that it comes from raspberries masks the fact that this is a compound that is an oil more closely compared to cayenne than the raspberry fruit.  It has effects on hormone receptors in the breast, with the test tube effects being positive.  But no one has done the long term human studies on high doses.

Yep, when you get down to it,  4-(4-hydroxyphenyl)butan-2-one bears about as much relation to raspberries as say, a pharmaceutical drug.  It isn’t something your body takes in and says “Oh, thank you!  Raspberries!”  In the rats it gets absorbed and urinated out.  No one asked the rats how they felt on the ketones.  But then again, they were taking 1% of their food as ketones.

Bottom line:  maybe this is the next miracle food.  I’m still working on my safflower oil diet.  I’ll get to ketones next month.

Planta Med. 2010 Oct;76(15):1654-8. Epub  2010 Apr 27.

Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes.


Nutrition & Functional Food Research Team, Korea Food & Drug Administration, Seoul, Korea. parkks71@kfda.go.kr


Raspberry ketone (RK) is a natural phenolic compound of the red raspberry. The dietary administration of RK to male mice has been reported to prevent high-fat diet-induced elevation in body weight and to increase lipolysis in white adipocytes. To elucidate a possible mechanism for the antiobesity action of RK, its effects on the expression and the secretion of adiponectin, lipolysis, and fatty acid oxidation in 3T3-L1 were investigated. Treatment with 10 µM of RK increased lipolysis significantly in differentiated 3T3-L1 cells. An immunoassay showed that RK increased both the expression and the secretion of adiponectin, an adipocytokine mainly expressed and secreted by adipose tissue. In addition, treatment with 10 µM of RK increased the fatty acid oxidation and suppressed lipid accumulation in 3T3-L1 adipocytes. These findings suggest that RK holds great promise as an herbal medicine since its biological activities alter the lipid metabolism in 3T3-L1 adipocytes.

© Georg Thieme Verlag KG Stuttgart · New York.

PMID: 20425690
Life Sci. 2005 May 27;77(2):194-204. Epub  2005 Feb 25.

Anti-obese action of raspberry ketone.


Department of Medical Biochemistry, Ehime University School of Medicine, Shigenobu-cho, Onsen-gun, Ehime 791-0295, Japan. chie@m.ehime-u.ac.jp


Raspberry ketone (4-(4-hydroxyphenyl) butan-2-one; RK) is a major aromatic compound of red raspberry (Rubus idaeus). The structure of RK is similar to the structures of capsaicin and synephrine, compounds known to exert anti-obese actions and alter the lipid metabolism. The present study was performed to clarify whether RK helps prevent obesity and activate lipid metabolism in rodents. To test the effect on obesity, our group designed the following in vivo experiments: 1) mice were fed a high-fat diet including 0.5, 1, or 2% of RK for 10 weeks; 2) mice were given a high-fat diet for 6 weeks and subsequently fed the same high-fat diet containing 1% RK for the next 5 weeks. RK prevented the high-fat-diet-induced elevations in body weight and the weights of the liver and visceral adipose tissues (epididymal, retroperitoneal, and mesenteric). RK also decreased these weights and hepatic triacylglycerol content after they had been increased by a high-fat diet. RK significantly increased norepinephrine-induced lipolysis associated with the translocation of hormone-sensitive lipase from the cytosol to lipid droplets in rat epididymal fat cells. In conclusion, RK prevents and improves obesity and fatty liver. These effects appear to stem from the action of RK in altering the lipid metabolism, or more specifically, in increasing norepinephrine-induced lipolysis in white adipocytes.

Bioorg Med Chem Lett. 2010 Apr 1;20(7):2111-4. Epub  2010 Feb 21.

Effect of essential oils, such as raspberry ketone and its derivatives, on antiandrogenic activity based on in vitro reporter gene assay.


Department of Environmental Bioscience, Meijo University, Nagoya 468-8502, Japan.


The effect of essential oils, such as raspberry ketone, on androgen (AR) receptor was investigated using a MDA-kb2 human breast cancer cell line for predicting potential AR activity. Among them, eugenol had the highest AR antagonistic activity with its IC(50) value of 19 microM. Raspberry ketone, which has threefold higher anti-obese activity than that of capsaicin, also had AR antagonist activity with its IC(50) value of 252 microM. Based on these findings, a more precise CoMFA model was proposed as follows: pIC(50) [log (1/IC(50))]=3.77+[CoMFA field terms] (n=39, s=0.249, r(2)=0.834, s(cv)=0.507, q(2)=0.311 (three components).

2010 Elsevier Ltd. All rights reserved.

PMID: 20226658
Growth Horm IGF Res. 2008 Aug;18(4):335-44. Epub  2008 Mar 5.

Effect of topical application of raspberry ketone on dermal production of insulin-like growth factor-I in mice and on hair growth and skin elasticity in humans.


Department of Translational Medical Science Research, Nagoya City University Graduate School of Medical Sciences, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.


Sensory neurons release calcitonin gene-related peptide (CGRP) on activation. We recently reported that topical application of capsaicin increases facial skin elasticity and promotes hair growth by increasing dermal insulin-like growth factor-I (IGF-I) production through activation of sensory neurons in mice and humans. Raspberry ketone (RK), a major aromatic compound contained in red raspberries (Rubus idaeus), has a structure similar to that of capsaicin. Thus, it is possible that RK activates sensory neurons, thereby increasing skin elasticity and promoting hair growth by increasing dermal IGF-I production. In the present study, we examined this possibility in mice and humans. RK, at concentrations higher than 1 microM, significantly increased CGRP release from dorsal root ganglion neurons (DRG) isolated from wild-type (WT) mice and this increase was completely reversed by capsazepine, an inhibitor of vanilloid receptor-1 activation. Topical application of 0.01% RK increased dermal IGF-I levels at 30 min after application in WT mice, but not in CGRP-knockout mice. Topical application of 0.01% RK increased immunohistochemical expression of IGF-I at dermal papillae in hair follicles and promoted hair re-growth in WT mice at 4 weeks after the application. When applied topically to the scalp and facial skin, 0.01% RK promoted hair growth in 50.0% of humans with alopecia (n=10) at 5 months after application and increased cheek skin elasticity at 2 weeks after application in 5 females (p<0.04). These observations strongly suggest that RK might increase dermal IGF-I production through sensory neuron activation, thereby promoting hair growth and increasing skin elasticity.

Xenobiotica. 1982 Apr;12(4):249-57.

The metabolism of 4-(4-hydroxyphenyl)butan-2-one (raspberry ketone) in rats, guinea-pigs and rabbits.


1. The metabolism of 4-(4-hydroxyphenyl)butan-2-one(raspberry ketone) was studied in rats, guinea-pigs and rabbits. 2. Following intragastric dosage (1 mmol/kg) urinary metabolite excretion was nearly complete within 24 h, amounting to roughly 90% of the dose in all species. 3. The most prominent urinary metabolites were raspberry ketone and its corresponding carbinol, both largely conjugated with glucuronic acid and/or sulphate. The extent of ketone reduction was greatest in rabbits. 4. Oxidative metabolism included ring hydroxylation and side-chain oxidation. The latter pathway led to 1,2- and 2,3-diol derivatives. It is proposed that the latter undergo cleavage to furnish the C6-C3 and C6-C2 derivatives detected.

PMID: 7113261

8 Replies to “Raspberry Ketones: What Is The Evidence Beyond Dr. Oz?”

  1. Thank you! I really applaud Dr. Oz’s encouragement of people to do weight loss, and maybe ketones will work for some. But I’d hate to have someone put all her faith in ketones, particularly at the 100 mg dosage.

    Thanks for helping me get the word out!

  2. Thanks for loads of information. I usually search for weight loss programmes online and there a lot to choose from depending upon individual to choose which better suits his/her lifestyle and body kind as different people have different body kind and metabolism.
    http://www.myweightlossclinics.com FOR Diet Clinic.

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