Evidence Update and Review for Yunnan Baiyao

In 2010 I first evaluated the Chinese herbal remedy known as Yunnan Baiyao, and I have reviewed additional evidence repeatedly since (1, 2, 3). So far, I have found little reason to believe claims that this remedy can stop bleeding in veterinary patients.

The ingredients are poorly described and not regulated or standardized, as is always the case with Traditional Chinese Medicine (TCM) remedies, and it is unclear if they have all been disclosed since the recipe is consider a commercial secret. TCM remedies have frequently been found to contain toxins and unreported pharmaceuticals, and some YB tested has been found to contain low levels of toxic substances. The TCM theory for how it works, involving movement of blood and mystical and ill-defined entities such as Qi, is inconsistent with established scientific understanding of physiology and blood clotting mechanisms. There are a number of more scientific theories for how the many chemicals in the product might affect bleeding, but none have been properly validated, and it is recommended primarily on the basis of tradition and anecdote.

Of course, despite the implausibility and lack of a clear mechanism, some clinical research has been done. In humans, the most recent review (from a source known to be biased in favor of TCM treatments, c.f. 3, 4) found some evidence of effect but also found that 1) most of the published research was of low quality and high risk of bias, 2) for some conditions the apparent effect disappears when lower quality studies are excluded, and 3) there is evidence of publication bias, in which negative studies remain unpublished creating an inaccurate impression of the true state of the evidence.

Such weak evidence might justify further research, ideally beginning with full identification of components, basic physiologic and pharmacologic studies, and then progressing through pre-clinical studies before clinical trials, as is the appropriate and expected course of investigating new medications. However, the current evidence does not really justify routine clinical use.

There is also some research into Yunnan Baiyao in veterinary species, and I have reviewed this in my previous posts. A couple of new small studies were recently presented at the American College of Veterinary Internal Medicine (ACVIM) annual forum, so I thought it would be worth reviewing those and summarizing the evidence to date.

Recent Studies
MacRae R. Carr A. The Effect of Yunnan Baiyao on the Kinetics of Hemostasis in Healthy Dogs. ACVIM  Forum, National Harbor, MD, 2017.

The goal of this study was to evaluate the effect, if any, of Yunnan Baiyao on laboratory measures of blood clotting and to look for any obvious, short-term adverse effects. Six laboratory dogs were given the product once a day for six days and clotting measures compared before and during the treatment. No harmful effects were reported, and there was no change in any measure of blood clotting.

Adelman L. Olin S. Egger CM. Stokes JE. Effect of Oral Yunnan Baiyao on Periprocedural Hemorrhage and Coagulation in Dogs Undergoing Nasal Biopsy. ACVIM Forum, National Harbor, MD, 2017.

The abstract begins with the statement, “The hemostatic efficacy and safety of Yunnan baiyao (YB) has been demonstrated across multiple species.” This isn’t actually accurate, and it reveals a pretty clear bias on the part of the investigators, which is relevant when looking at the methods and conclusions of the study.

Nineteen dogs having nasal biopsies were randomized to Yunnan baiyao or placebo before having nasal biopsies taken, which commonly causes some bleeding. A variety of outcome measures were evaluated, including laboratory values associated with clotting and assessments of how much blood was lost and how long it took the dogs to clot after biopsy. The report indicates appropriate blinding of investigators, caretakers, and statisticians. However, not all dogs were assessed with the same measures, which introduces some inconsistency and variability into the results.

Time for bleeding to stop- Exactly how this was measured is not described. The YB group ha d a slightly shorter BMBT (300+/- 12 seconds vs 367+/- 9 seconds). Several other variables (age, history of nosebleeds, blood pressure, and number of biopsies taken) were also associated with the BMBT, though the details were not reported.

BMBT (time for bleeding to stop from a standardized cut on the gums)- There was no difference between the groups.

TEG (a lab measure of clotting)- There was no difference between the groups.

Total blood loss- It is also not clear how this was measured. There was no difference between the groups.

Despite the failure to find an effect for most measures and the questionable clinical significance of the one difference seen (a difference from 46 to 88 seconds in the time for bleeding to stop), the authors naturally conclude that the study supports using YB routinely before this type of procedure.

Veterinary Evidence Summary
The table below lists all of the actual in vivo studies in veterinary species I have found. It also lists some key features of these studies that help evaluate how reliable their results are, including the number of animals studied, the use of key methods for preventing bias, such as randomization, blinding, and a control group, and the outcomes.

Table 1. Studies of Yunnan Baiyao in veterinary species.

Of these ten studies, 5 found no effect at all, and 2 others showed mixed results, with possible effects in some measures evaluated in the studies but not in others. Of the three fully positive studies, two did not report any of the major methods for controlling for possible bias and other sources of error.

Overall, this is a very unconvincing set of data. Even clearly ineffective methods can have some positive studies due to bias and error alone, so the lack of a clear, consistent pattern of expected effects is troubling. Not all of the studies used the same measures, so it is possible the product could have some clinical effects by some mechanism that doesn’t affect the laboratory measures of clotting usually used, but that is a big stretch.

It is also worth noting that the studies showing some effect didn’t look find any benefit in terms of clinically important outcomes, such as survival, need for transfusion, etc. Even under the most optimistic assessment of the evidence, it may be that Yunnan Baiyao speeds clotting in the case of small wounds by a few minutes, but this may not necessarily have any meaningful benefit for actual patients.

Bottom Line
The TCM rationale for using Yunnan Baiyao is part of an unscientific, quasi-religious belief system and cannot be accepted as a sufficient basis for using an otherwise unproven remedy on patients, especially when the ingredients in that remedy are not fully disclosed or regulated for quality, consistency, and safety. The more plausible scientific hypotheses for how Yunnan Baiyao might work remain unproven.

The clinical research evidence is mostly negative, and even positive studies have not shown any significant effects on clinically meaningful objective outcomes.  No clear evidence of harm has yet been found, though the limited nature of the evidence does not ensure that the product is truly safe.


Ogle CW, Soter D, Cho CH (1977) The haemostatic effects of orally administered yunnan bai yao in rats and rabbits. Comparative Medicine East and West 5:2, 155-160

Ogle CW, Dai S, Ma JC. The haemostatic effects of the Chinese herbal drug Yunnan bai yao: A pilot study. Am J Chin Med (Gard City N Y) 1976;4:147–152.

Graham L, Farnsworth K, Cary J (2002) The effect of yunnan baiyao on the template bleeding times and activated clotting times in healthy ponies under halothane anesthesia. Journal of Veterinary Emergency and Critical Care 12:4; 279; 2002 (abstract only)

Epp TS, McDonough P, Padilla DJ, et al. The effect of herbal supplementation on the severity of exercise-induced pulmonary haemorrhage. Equine and Comparative Exercise Physiology 2005;2:17-25.

Fan C, Song J, White CM. A comparison of the hemostatic effects of notoginseng and yun nan baiyao to placebo control. J Herb Pharmacother 2005;5:1–5

Murphy LA, Panek CM, Bianco D, Nakamura RK. Use of Yunnan Baiyao and epsilon aminocaproic acid in dogs with right atrial masses and pericardial effusion. J Vet Emerg Crit Care (San Antonio). 2016 Sep 26. doi: 10.1111/vec.12529. [Epub ahead of print]

Frederick J, Boysen S, Wagg C, Chalhoub S. The effects of oral administration of Yunnan Baiyao on blood coagulation in beagle dogs as measured by kaolin-activated thromboelastography and buccal mucosal bleeding times. Can J Vet Res. 2017 Jan;81(1):41-45.

Lee A. Boysen SR. Sanderson J. et al. Effects of Yunnan Baiyao on blood coagulation parameters in beagles measured using kaolin activated thromboelastography and more traditional methods. International Journal of Veterinary Science and Medicine. 2017;5(1):53–56.

MacRae R. Carr A. The Effect of Yunnan Baiyao on the Kinetics of Hemostasis in Healthy Dogs. ACVIM  Forum, National Harbor, MD, 2017.

Adelman L. Olin S. Egger CM. Stokes JE. Effect of Oral Yunnan Baiyao on Periprocedural Hemorrhage and Coagulation in Dogs Undergoing Nasal Biopsy. ACVIM Forum, National Harbor, MD, 2017.

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26 Responses to Evidence Update and Review for Yunnan Baiyao

  1. Bill Burley says:

    Excellent reply and commentary. TCM ‘herbs’ are 99% pre-scientific quackery. It’s impossible to know precisely what chemical compounds are in them. Many ‘medicines’ are mixtures of five or more substances. And ‘substitution’ without notification or labeling is a routine part of TCM, not to mention the possible toxic ingredients or contaminents. (recall the Aristolochia furor…)
    I wrote on all this in SRAM (Scientific Review of Alternative Medicine) Vol 4, #2 Fall/Winter 2000, a piece titled “Chinese Herbs, Some Things to Remember.” Sad to say, the situation in today’s markets for these ‘herbs’ is not much better than it was 15-20 years ago. Caveat Emptor in the extreme.

  2. Jeannine Mallory says:

    Interesting insight. I used Yunnan Baiyao for my elderly Golden Retriever, who had an inoperable mass in one of her nostrils that caused frequent nosebleeds. I put it in her food twice a day.
    My personal belief is that TCM has been around for a very long time, and sometimes these treatments work. My Golden’s nosebleeds were several times a day and heavy. After she had been on Yunnan Baiyao for almost a week, I suddenly realized that her nosebleeds – while still occurring – had decreased in frequency and severity.
    Can I say with certainty that the Yunnan Baiyao caused this improvement? No. Of course not. My Golden suddenly showed increased interest in broccoli, so I mixed it in with her food once every day or so. After she passed away, I thought about how much she loved broccoli (especially frozen), so I did some reading and asked a few people. I learned that broccoli, and some other vegetables, is a great source of Vitamin K, which is important in helping blood clot. Somehow, intuitively, she knew this.
    So maybe it was the Yunnan Baiyao; maybe the broccoli. Or maybe both.

  3. skeptvet says:

    So maybe it was the Yunnan Baiyao; maybe the broccoli. Or maybe both.

    Or maybe something else we haven’t thought of. That’s the problem with our personal experience, it can’t really identify causation very well.

  4. Rebecca Diaz says:

    I realize that evidence based medicine is necessary and what we should strive to give our patients. However, I practised veterinary medicine in Guam where many of my patients carried diseases that interferred with clotting. I started using Yunnan Bai Yao about two years into my career. I will never practice in the tropics without this herb. While I cannot give you exact measurements I am 100% covinced that this herb reduced morbidity and mortality among my patients.

  5. skeptvet says:

    People have been equally certain of the value of bloodletting, homeopathy, ritual sacrifice, and absolutely every other ineffective treatment ever tried. The bottom line is that science is more reliable than our personal experiences and when we trust anecdotes and clinical experience over real evidence, we are almost always wrong.

  6. Betsy says:

    I’m sure you won’t change your mind, but I keep YB around because we live where rattlesnakes occur. My parents came for a visit and within 15 minutes their dog was bitten by a small rattler when she stepped near it. We heard her yelp and saw her jump away, and there was the snake coiled. I immediately gave her YB and we jumped in the car to travel to the ER vet 45 minutes away. They found her painful with bruising up her leg, but not a lot of swelling of the leg. They never could find the actual bite as there were no visible punctures and no blood seeping out as happened to my cat, who endedup with skin sloughing at the bite site. I did not give the cat YB, BTW, as we discovered the bite well after it had happened. Their dog came home the next day after antivenin treatment.

  7. skeptvet says:

    Unfortunately, such stories don’t help us decide what works and what doesn’t. I, for example, have seen dozens of rattlesnake bites in practice. Some are dry bites and show no symptoms at all, others have mild, localized pain and swelling, and a few get critically ill. About half of owners can’t afford antivenin, so many patients don’t get it. None have ever gotten YP, yet all have recovered and gone home, most a day or two after the bite. There is simply no reason to think YB should help with this problem, and since most dogs recover fine without it, there is no reason to think it did anything for your dog. Of course, my experiences won’t change your mind either, which is part of why we are better off relying on scientific data than personal experience in such matters.

  8. Arden Allen says:

    My dog has recently been diagnosed with hemangiosarcoma. It presented as a mass of blood in her abdomen. Her spleen was removed and going on 19 days she has recovered well. But the vet put her on YB and I’m-Yunity. I read the PennU study of 15 dogs, one living for 199 days. I think this Chinese medicine stuff is a palliative for me and does nothing for my dog. I wish I was wrong. She’s also getting Propranolo, which has years of study behind its effect on cancer. I’m going to get her on a metronomic chemotherapy and hope I have her for a while longer. It goes without saying my dogs mean a lot to me.

  9. skeptvet says:

    I’m sorry you’re going through this. I lost a dog to hemangiosarcoma once, and it is a terrible disease. I agree that the research on Yunan Baiyao and I’m Yunity are not very convincing, but I understand why vets and owners sometimes grasp at such straws. Good luck!

  10. Ruth Frassetto says:

    I trust Chinese medicine and it works. My dog was given two days to live. Vet wanted to remove spleen and a bleeding tumor next to it. My dog is 14, his blood platelets were way down. I said no to the surgery. My goal was to take him home care for him for his last days and then when things got bad put him down. I was prescribed this herb and my dog is stilll here. His gums and tongue are pink, he is doing great. Whatever this herb is it stopped the bleeding. I researched what foods would increase his blood platelets. I let him sleep as much as he needed. Let him eat whatever he fancied made sure he was hydrated and we went for a nice walk today. Day 4??

  11. skeptvet says:

    Sorry, but the fact that the bleeding stopped after you gave something doesn’t mean what you gave stopped the bleeding any more than the fact that it rosins after you wash your car means washing your car caused it to rain. Many dogs with bleeding hemangiosarcoma lesions have periods of bleeding which clot spontaneously and then recur days to weeks later without any treatment at all. I hope for the best for you and your dog, but your experience doesn’t say anything about the value of YB.

  12. Johan Lippanauer says:

    It’s reputation in the jungle fields of battle speaks for itself .and the key herb, Tienchi or San Qi, is well documented all by itself. Your fears are ungrounded.

  13. skeptvet says:

    Sorry, but “reputation” is just anecdote, and anecdote is consistently unreliable. More people swore by the value of bloodletting and animal sacrifice in healing than swear by Yunan Baiyao now, so without scientific evidence, stories don’t mean anything.

    Here’s some more detailed discussion of this problem.

    Why Anecdotes Can’t Be Trusted

  14. Will Oliver says:

    My Veterinarian recommended I try Yunnan Baiyao capsules to treat my dog’s expressing blood in his urine. Since the little guy has bladder cancer and has gone through a number of meds for treatment the Doctor wished to add something effective without side-effects or would interfere with the other drugs. The staff was quick to fill my order and I received it within a few days even though I am on the opposite end of the U.S. I started out using two 250mg tablets a day, which was double the recommended, and within a week the bleeding stopped. The Yunnan Baiyao was reduced to once a day and the bleeding remained under control. Unfortunately it didn’t help with the pain, so my Vet had to put him on Tramadol and Gabapentin, but the Yunnan Baiyao also didn’t reduce the effectiveness of these drugs. My dog is now going pretty much normally for a canine his age (13 yo) and has returned to his lively self. Today I order and additional two packs for next month and within a few hours received notification of shipment. I would highly recommend the Yunnan Baiyao capsules if you have a dog with urinary bleeding (after checking with your Vet of course) and believe you cannot find a better deal from friendly people who ship an order so quickly.

  15. skeptvet says:

    While it’s great that your dog is doing well, it’s important to understand that such anecdotes exist for every medical treatment ever tried, and they are just as easy to find for treatments that don’t work or are harmful as for those that help. It is always risky to trust anecdotes over scientific evidence, and the evidence so far shows no reason to think YB is helpful for cancer. The idea of something that helps without side-effects is a myth, since in medicine there are risks for anything that has benefits, though without scientific testing we often don’t know what the risks are.

    Here is Why Anecdotes Can’t Be Trusted“>some more detail on why anecdotes are so unreliable

    I would also point out that there is good evidence oral tramadol is not an effective pain reliever for dogs, and the jury is still out on gabapentin since there is little research evidence for it, so I hope that these are not the only pain relievers your friend is getting.

  16. Thane Katz says:

    Here’s my opinion whether you want it or not. 🙂 My vet also recommended using Yunnan Baiya0 for my 16 1/2 year old whippet with bleeding cancers on his skin. It stopped the progression of the skin cancers. My opinion is that it works and that is also the opinion of my vet, who I highly admire and trust. So who knows, if I hadn’t started giving it, Riley may have been gone by now. If you’re giving it for something that will eventually end your dog’s life, why not give it a try when there’s a chance it could help? When it comes to the point in your dogs life when the end is near, why not give something that might relieve the symptoms of their ailment at least? One thing to be aware of however if you are using Yunnan Baiyao is to make sure it is manufactured by Yunnan Baiyao Group Co., Ltd.

  17. skeptvet says:

    Glad your pet is doing well, but I have to point out, yet again, that such anecdotes prove nothing. There is no reason to think YB can affect skin cancer, the evidence shows it probably does not stop bleeding, and the fact that your pet proved after taking it can have all kinds of explanations other than the one you choose to believe. We also have no idea if it is safe since the company won’t say what is in it and many herbal remedies have turned out to contain harmful toxins.

    Here is more about why anecdotes don’t tell us the real story.

    Why Anecdotes Can’t Be Trusted

  18. Teresa says:

    Horse racing is a multi-million dollar sport. And owners and jockeys take the health of the horses very seriously. So what are they using with their race horses to control EIPH with extreme success? That’s right…


    And I’ve been using it for my schnauzer with hemangiosarcoma for months with great success. We’ve had to use the red pill a couple of times, but she is pain free and functioning very well in spite of her diagnosis.

  19. skeptvet says:

    The idea that people believe in something is evidence for that belief is a classic fallacy. And the idea that they aren’t likely to be wrong in that belief because there is money riding on the answer and they care a lot about the problem doesn’t fit reality. People wasted millions of dollars on dowsing rods as bomb detectors in Iraq when the consequence of false believe was death, and that didn’t make the belief any more accurate. If all the evidence is negative (and almost all of it is), it really doesn’t matter at all how many people believe for anecdotal reasons.

  20. Tony says:

    Thank you for your interesting article on this product. In my residency currently, I see a lot of evidence-based medicine admixed with a few perpetuated, anecdotal and pre-scientific practices. I appreciate your work to promote scientific reasoning, and appropriate skepticism when it comes to our field!

  21. skeptvet says:

    Thanks, I’m glad the article was useful.

  22. Jenn H says:

    I appreciate the importance of pointing out the differences between scientific, evidence -based and anecdotal evidence.
    It would be more helpful if you offered scientifically proven alternatives when available.
    All the criticism of alternative treatments without offering another option just makes you seem like a narrow minded cranky person who just wants to crap all over things you don’t like.
    Offering science based suggestions that can be discussed with our vets would be more helpful & productive.

  23. skeptvet says:

    The alternative, of course, is to evaluate all therapies scientifically and choose those with the strongest evidence. That is what I do in clinical practice, and you will certainly find plenty of articles here explaining what the most science-based approach is for particular problems.

    However, it is not up to me to provide an answer to every possible question. And in the case of Yunan Baiyao, the fact that it clearly doesn’t work is good reason not to use it. The fact that there is no alternative proven to work doesn’t change that fact. Science is about understanding the world as it is, and it may not always give us the answers we want when we want them, but that doesn’t justify turning to pseudoscience.

  24. Jade N. says:

    Bias is the worst enemy of progress.

  25. Isopodora says:

    Do you think it can slow the growth of cancer cells when taken by an actual dog like some claim or only in a dish? Do you think CBD for terminally ill canines is any good?

  26. skeptvet says:

    Until it is tested in actual dogs, we don’t know whether the effects seen in cell culture will apply. As I often point out, bleach kills cancer cells in culture, but obviously it isn’t a useful drug, so the translation from model to real patient is often not straightforward.

    The only decent evidence so far for CBD in dogs is for arthritis pain, so if there is pain not adequately managed with other treatments, it might be useful for that. It is unclear if it would help for any other common palliative care needs.

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