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Weight loss with oolong (or wu-long) tea – miracle drug or marketing hoax?

[- picture of obese man -]We’ve recently received multiple questions about wu-long tea in regards to advertised slimming properties, so I’ve decided to shed some light onto the subject.

(People are often confused by the terminology used in advertisements for “wu-long slimming teas”. These advertisements seem to always use the more exotic sounding word wu-long, but both terms, oolong (generally used in English) and wu-long (generally used in Chinese), refer to the same kind of semi-oxidized tea. I’ll use the commonly used term oolong throughout this article.
Please visit our oolong information page for more general information on oolong tea.)

The story behind reported (advertised) weight losses based on the consumption of oolong tea

It seems that clever marketers have found a way to cash in on findings from recent scientific research on the fat-burning and anti-obesity properties of oolong tea.
In China, oolong tea has been reputed to help regulate body weight and increase metabolism for centuries. In recent years, a number of studies have been conducted on humans and laboratory animals to investigate the validity of this belief.

The recent surge of interest was probably caused by the latest publication on the topic by a group from the Nanjing Institute for Pediatrics led by Guo Xirong who conducted a 5-year study on childhood obesity. Amongst other findings that help to understand and control the development of obesity in children, the group confirmed that “the continuous intake of oolong tea contributes to enhancing the function of fat metabolism and to controlling obesity” (the press release titled Oolong tea helps you lose weight can be found here).
This recent study was preceded by a number of earlier studies with similar results.
W. Rumpler et al. from the Beltsville Human Nutrition Research Center, USA together with colleagues from the Department of Nutrition, University of Tokushima, Japan have published a study titled Oolong tea increases metabolic rate and fat oxidation in men in 2001 that investigated the effects of oolong tea consumption on energy expenditure (EE) of humans. The study focused on men between 25 and 60 years of age and the results show that while the consumption of oolong tea lead to an increase in EE of merely 3-4%, fat oxidation was increased by 12% in the group that consumed oolong tea (click here for the full text of the study).
A Japanese study titled Anti-obesity action of oolong tea presented the results of an investigation on the effects of oolong tea in a high-fat diet. The study was conducted on obese mice and the scientists found that while the consumption of oolong tea didn’t lower the mice’s appetite (i.e. food consumption stayed constant), it prevented obesity and fatty liver that was observed in the control group where oolong tea was replaced by water (for the full text of the study, follow this link).

Why oolong tea?

Results of the cited studies indicate that the observed effects of oolong tea consumption on fat oxidation and EE can be attributed largely to caffeine intake. But the studies observed greater effects resulting from tea consumption than from caffeine alone, so a synergistic effect of caffeine and the catechins contained in tea seems plausible.
An explanation for this could be the reported effect of tea polyphenols (i.e. catechins) on controlling the deposition of triglyceride (a chemical formed in our liver by the synthesis of sugar and fat and – if present in excess – ultimately deposited in fat cells). Polyphenols are reputed to activate certain enzymes that dissolve triglycerides and could therefore play an important part in controlling fat deposition. Since oolong tea contains high levels of polyphenols, it could be this effect that was observed in the cited studies.

Miracle or hoax?

A bit of both, really. As we’ve seen above, there is fairly conclusive scientific evidence that oolong tea DOES help controlling body fat.
However, the miraculous effects advertised by some dubious online vendors are just what they seem: too good to be true!
Oolong tea DOES NOT make you lose 30kg in 30 days (if you’re not changing the rest of your diet), but it is a great (and I haven’t mentioned yet – delicious!) way to help you control weight in conjunction with physical exercise and a healthy diet.

I want to conclude this article with a quote from W. Rumpler et al., which sums up quite nicely my feelings about this subject:

It is clear that consumption of oolong tea stimulates both EE and fat oxidation in normal weight men. This raises the possibility that tea consumption could have some beneficial effect on an individual’s ability to maintain a lower body fat content. However, any beneficial effect would only be realized if the effect was sustained upon chronic consumption of tea and the individual did not compensate with greater food intake in response to tea consumption.

We are offering currently about 15 different oolong teas from China and Taiwan (Formosa). Amongst them, we carry the famous Wuyi Rock Tea (Wu Yi Yan Cha) and many varieties of Taiwanese high mountain oolong (gao shan).
Please see our current pricelist for an overview of our extensive range of oolong teas.

[techtags: oolong, wu-long, wulong, tea, weight loss, slimming tea, polyphenols, obesity, burning fat]

34 Responses to Weight loss with oolong (or wu-long) tea – miracle drug or marketing hoax? »»


  1. Comment by michael | 2007/08/10 at 08:57:55

    Good info! But I’m still not entirely clear as to whether oolong tea just helps to prevent obesity or whether it has any influence on existing fat reserves as well.

  2. Jo
    Comment by Jo | 2007/08/10 at 23:43:40

    although the studies that I mentioned in this article don’t explicitly state this to be true, there is a citation in Rumpler’s publication of a study on 102 Chinese women who lost more than one kilogram of body weight over a period of 6 weeks.
    But I think the presented results of an increase of fat oxidation would be effective on existing fat reserves as well.

  3. Comment by Tea Laden | 2007/08/11 at 04:30:46

    Thank you for this article – just so you know how bad this one company is that is marketing the “slimming tea”; their lawyers sent us a cease and desist letter that indicated they trademarked the word WU-LONG and we were not allowed to use it to describe oolong tea. They indicated that the word did not exist until they started using it in 2002.

  4. Comment by Paul | 2007/08/12 at 09:02:04

    Very interesting article. I have often seen wu-long teas advertised on the internet (they seem to show up every time you search for diet-related terms on google) and have visited one or two of the sites.
    The promises really “seem to good to be true”. Thanks for sharing the information with the rest of us.
    You might be interested in reading this article (http://hubpages.com/hub/The_Truth_About_Wu-Yi_Tea), it has a very long comments list where people share their experiences.
    So long,

  5. Jo
    Comment by Jo | 2007/08/12 at 09:12:22

    Tea Laden: Thanks for that info. Although I can’t really imagine how you could trademark a common term I’m trying to understand what happened there. Do you know whether that trademark is real? Did they trademark the hyphenated version? What did you do? Did you sign anything?

    Paul: Thanks for the link. I have read Maddie’s article a while ago (and commented on it). It seems it gets quite a bit of attention (and after Tea Laden’s comment I’m wondering whether Maddie has gotten a cease and desist letter), so I guess there’s some need for education out there to help the confusion.
    …one of the reasons I wrote this article…

  6. Comment by Tea Laden | 2007/08/16 at 04:04:10

    The trademark is pending and I believe the trademark and patent office has sent them a refusal email based on the information in the TESS system at the patent and trademark uspto.gov website. In my opinion this company gives the tea industry a bad name just by the way they market their wulong tea. The Electronic Retailers Self-Regulating Program (ERSP) has recommended that they change the claims and the way they market their wulong. This links to the ERSP findings and is an interesting read.

  7. Jo
    Comment by Jo | 2007/08/16 at 13:34:26

    Thanks for the link, it is indeed a very interesting read. I love the concept to base the rarity claims on the small percentage (2%) of oolong tea in the general tea market (which still makes it many, many tons of tea).
    I guess a more clever approach would have been a claim to the relative rarity of Wuyi oolongs, although nobody in the business would consider average wuyi rock teas to be rare (GOOD wuyi oolongs can be very rare, though!).
    Well, I guess I’ll pour myself a nice Da Hong Pao now and contemplate the flavour rather than the rarity of this tea…

  8. Comment by So U. Know | 2007/08/29 at 03:13:46

    An interesting link and information regarding Okuma’s Wulong Slimming Tea: http://www.souknow.hyperphp.com

  9. Jo
    Comment by Jo | 2007/09/02 at 14:49:43

    Thanks for the link, interesting info on this page. It seems there is quite a lot of info about this scheme out there if you start digging…

  10. Comment by Weight Loss Tea | 2008/03/25 at 08:10:29

    Oolong seems great. Adding tea to my newly changed diet, I’m hoping will help me shed some pounds.

  11. Comment by Oolongtea | 2008/05/03 at 00:02:44

    hallo guys

    I am a big fan of oolong tea and really I love to drink this oolong tea. Actually it keeps me fresh & fit.

  12. Comment by Tracey Selwyn | 2008/12/06 at 08:48:29

    Thank you for all your information. It was actually hard to track whether wu-yi tea was for real or not. I can gather from reading your articles that oolong tea DOES have some properties – not just related to caffine – but also including polyphenols which help metabolise fat. From everything I have researched it looks as those oolong tea, in general, would be a viable assistant in a weight-loss plan. Can I be assured in saying that this relates to all oolong and not just the wu-yi type??

  13. Jo
    Comment by Jo | 2008/12/08 at 17:55:58

    Hi Tracey,
    sorry for my delayed reply, but I was out of town.
    You are absolutely right with your statements (I’m glad someone actually understands what I’m writing). It’s also good to see that people like yourself are doing their homework before falling for marketing slogans.
    While some suppliers of WuYi oolongs suggest that these type of oolongs are the only or at least the best tea for weight loss, there is no real evidence in the published medical studies to support this. Neither one of the research papers reports the type of oolong used in the study and therefore, one is left to assume that all type of oolong tea are equally suited to assist with weight loss.

  14. Comment by Jannine | 2009/03/26 at 11:40:10


    We have tried slimming tea and coffee and we have great results. I have lost 10kg in 11 weeks and my husband has lost 8kg in 9 weeks.

    We have not changed our diet but the drinks supress your apetitite so you eat less and therefore lose weight.

  15. Jo
    Comment by Jo | 2009/03/26 at 22:47:22

    Hi Jannine,
    that’s good news. I’m glad to hear that oolong tea worked for you.

  16. Comment by ZACHARY | 2009/04/28 at 07:00:29

    Maybe this is not a question about tea choice and its consumption and not about personal weight, but still about autosuggestion and when it works that simply just great! Anyway, thank’s for the info, I like to consume such knowledge

  17. Comment by Maisie | 2009/04/29 at 03:17:18

    15 different kinds of oolong tea? What an enormous diversity, but I don’t feel myself rather competent to make the right choice. What are the main criteria to distinguish them?

  18. Jo
    Comment by Jo | 2009/04/29 at 19:45:48

    Hi Maisie,
    criteria of distinction are level of oxidation (low oxidation green vs. high oxidation dark oolongs), level of roasting.
    In the end it boils down to personal flavour preferences.

  19. Comment by Sally Dickson | 2009/07/01 at 10:53:57

    Can You send me some information on which tea you have is the best for weight loss please.
    I enjoy green tea.


  20. Jo
    Comment by Jo | 2009/07/03 at 06:53:59

    Hi Sally,
    while most sources cite oolong tea as the best tea for weight loss, the Chinese traditionally drink pu-erh tea to control weight.
    But the flavour of pu-erh tea can be an acquired taste and for most people, oolong tea is easier accessible.
    Hope that helps.

  21. Comment by Cautious | 2009/10/10 at 07:08:09

    I am so glad that i chose to give Oolong tea a go in helping me lose weight as i been through many diet fads. Although i changed my diet slightly i am fitter now and have lost 10kgs. I feel healthier and am actually walking a lot more. For me that is a great accomplishment as anything physical was always daunting not anymore!!!

    It wont happen overnight but it will happen!!

    Its natural so its got to be good for you!!!!.

    Thank You(-:

  22. Comment by Mariscos | 2010/05/07 at 08:52:42

    I think the tea helps to loose some weight but don’t rely on ti as a magical solution, because it don’t, nothing inthis world makes miracles regarding to weight loss.

  23. Comment by Michelle | 2010/08/26 at 22:28:30

    Like some of the people above, I too stumbled upon a website proclaiming huge weight loss down to tea’s but in reading the fine print they cost a fortune! I feel positive about trying these teas ALONG with an altered (healthier) diet and exercise (which I have started anyway…)
    So… any recommendations with regards to taste? I would like to try a Oolong tea..
    Thanks for the great info!

  24. Jo
    Comment by Jo | 2010/08/29 at 14:07:26

    Hi Michelle,
    you’re welcome.
    I agree, most oolong teas that are advertised as weightloss tea cost multiple times what they’re worth and aren’t any more potent than other oolong teas (or, at least, aren’t proven to be more potent).
    My suggestion would be to go with personal taste. Greener oolongs (like a Tie Guan Yin or most Taiwanese oolongs) are more on the floral side, while more oxidized oolongs (like those from Wuyi) are more earthy, almost smokey with a mineral flavour.
    While most studies seem to focus on oolong tea in regard to weight control, other teas are more often used for that purpose in China, namely pu-erh tea and ‘dark’ tea (like Fu Cha). But these teas are relatively rarely available in the Western world and therefore of limited marketing interest.

  25. Comment by Daniel | 2010/12/06 at 20:36:17

    This is a very informative article, keep the great blogs coming!

  26. Comment by l. highs | 2011/04/07 at 00:38:11

    Thanks for sharing such informative topic. I truly learned something essential from your wonderful post. I haven’t tried this tea yet, but I would like to see it’s effect. Are there any side effect when taking this drink regularly?

  27. Comment by Regina Brown | 2012/09/15 at 09:12:17

    I came across Oolong tea by mistake on the internet. I researched it and finally purchased mine for $16 including shipping and handling. It contained 100 tea bags. I had lost some weight and got stuck at one weight and just could not come down. I also am hypoglycemia. I started drinking the tea 15 minutes before each meal. I weight myself every Friday. I started the tea one Friday after my weight in. The next Friday weight in, after the 3 cups a day, I lost 1.5 lbs. I told myself this was water weight. The next week I lost about 1 lb more and the next 1 lb. So in 3 weeks I have lost 1 lb a week. Plus my sugar level has not dropped since I started drinking the tea so I am not as hungry. I do eat the same at a normal meal but I do not have the in between meal cravings. Also, when my sugar would drop I would eat so much because I would feel like I am starving. I do watch my weight and always have but the older I get the higher it gets and the harder it has been to keep it at bay without starving myself.. So I say yes to Oolong. I have notice my face is breaking out a little and I think it has something to do with the tea. Hopefully that will all go away. I use to drink 3 cups of coffee a day. I replace two cups with the Oolong tea.

  28. Jo
    Comment by Jo | 2012/09/25 at 19:13:02

    Hi Regina,
    thanks for sharing your story here. I really appreciate it and it mirrors the feedback that I have received from many of my customers.
    My suspicion about the outbreaks in your face is that – due to detoxifying properties of the tea – your body is shedding built-up toxins. These come out in various forms and places, depending on the person. For some, it’s the face, unfortunately. But this should stop fairly soon.

  29. Comment by Jenny | 2014/04/08 at 02:14:01

    Do people really believe you can lose 30kg in 30 days just by drinking tea? I find it hard to believe anyone could be that gullible. However, tea in general, and green tea in particular, undoubtedly has a range of health benefits. One of those benefits may include a slight slimming effect but taken in isolation is hardly anything to get excited over.

  30. Comment by http://www.auckland-house.co.nz/newaboutus.php?2076jodans | 2014/11/15 at 10:26:39

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Trackbacks & Pingbacks »»

  1. Trackback by Anonymous | 2007/08/09 at 23:50:22

    Weight loss with oolong (or wu-long) tea – miracle drug or marketing hoax?…

    Have you ever wondered about the reported results from a new magical weight-loss drug called Wu-long Tea?
    This article from the owners of Ya-Ya House of Excellent Teas gives in-depth background info on the story……

  2. Trackback by Anonymous | 2007/10/25 at 12:00:35

    Wu Long tea – miraculous weight loss drug or marketing hoax?…

    This article provides an unbiased and objective overview about the heavily advertised slimming properties of oolong tea….

  3. […] Tea is good for your health The last decades have seen the emergence of many new diseases for humankind. Many of these diseases are related to an ever-increasing level of stress or to a change in our diet from comparatively natural food to heavily processed foods. Tea can help with both of these issues. Anyone who’s been to our teahouse or had a conscious tea session will know about the calming effects of tea. While it raises awareness (partly due to its caffeine content), it has also a soothing and relaxing effect on the mind. It is not uncommon that people come to the teahouse all stressed out and leave 3 hours later completely relaxed (sometimes to realize that they’ve missed an appointment an hour ago). Tea can help us to take a break, to slow us down. For more than the first half of its known existence, tea has been used primarily as a medicine. And although it is mostly enjoyed as an everyday drink today, it still plays an important role in Traditional Chinese Medicine. Different types of tea are used on a constitutional level to adjust imbalances like excessive heat in the body (green tea, white tea and young raw ’sheng’ pu-erh have a cooling effect on the body while oolongs, black tea and ripe ’shou’ pu-erh act as warming herbs). But beyond the deeper constitutional effects of tea, modern scientific research continually discovers a wealth of health-improving effects offered by the simple leaf of camellia sinensis. Tea has been shown to offer substantial benefits in such diverse areas as cancer prevention, anti-aging and weight-loss. (As a matter of fact, I’ll cover the new findings on health benefits of tea in a future article) […]

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