What Do We Know About Herbal Remedies and Menstrual Cramps? (Spoiler Alert: Not Much.)

herbalWhen I was entering adulthood and suffering from severe menstrual cramps, I suffered without relief for far too long. And I am certainly not alone in this experience. The most common gynecological disorder is dysmenorrhea — painful menstrual cramps — which strikes an estimated 90 percent of reproductive-age females. Furthermore, around 40 percent of American women use some form of complementary and alternative medicine, or CAM. “CAM” is a catchall for approaches to health care that fall outside of the mainstream. Given the popularity of CAM and the ubiquity of dysmenorrhea, it was no surprise that I experienced painful cramps, nor was it shocking that I tried a few herbal remedies, which are a type of CAM.

“Natural” doesn’t necessarily mean safe or effective, so be critical.

During my second year of college, at the age of 19, a friend recommended a couple of herbal remedies to add to my cramp-fighting arsenal. I tried them, but it was difficult to know if they really worked. My pain varied so wildly cycle to cycle that I had no way of knowing if I was just having a “good month” when I initially tried these products. Although I thought they worked at first, after I had accumulated more menstrual cycles under my belt, I started to wonder if my cramps were really any less painful. On average, I still seemed to be missing just as much school and work as before — but I wasn’t sure.

The problem was that I never collected any before-and-after data — I didn’t spend years ranking the severity and duration of my cramps, or keeping track of the hours spent in bed away from school, work, or other obligations. Furthermore, my initial sense of optimism could have colored my perceptions. Since we can be tricked by our own expectations and biases, it is important to have access to quality evidence — gathered in large, methodologically powerful studies.

Raspberry leaf tea was the first herbal remedy I tried. It tasted OK, and the ritualistic nature of drinking a hot beverage from a steaming mug was soothing. But is there any actual evidence that raspberry leaf can help relieve the pain of dysmenorrhea? Although it’s been used therapeutically since at least the 1500s, the only human studies I can find for any gynecological condition examine its use during pregnancy or labor — not for treating menstrual cramps. The only claims for raspberry leaf’s efficacy in treating cramps come from biased sources, like the manufacturers themselves. It seems the tea I drank during my late teen years had word of mouth and marketing going for it, but not much else.

But raspberry leaf tea is not the only herbal remedy that people might use to alleviate their dysmenorrhea. Through the grapevine, I heard tales of other cramp-fighting herbs, such as black cohosh and dong quai. Additionally, many herbal preparations contain multiple ingredients. For example, a review of Chinese herbal medicine for dysmenorrhea contained a list of the 21 most common ingredients used in such preparations, including rougui (cinnamon bark), puhuang (cattail pollen), and wulingzhi (flying squirrel feces). Although the authors of this review noted trials with promising results, the data available suffered from poor methodology, small sample sizes, or both. It seems that the vast majority of herbal remedies that are marketed for cramp relief aren’t well studied, which makes it difficult to know if they can actually help us.

To demonstrate how little we know about the efficacy of herbal remedies in treating dysmenorrhea, I decided to pick one product as an example. A local store carries a tincture that is marketed for the alleviation of menstrual cramps; it contains black cohosh, wild yam, dong quai, skullcap, silk tassel, lavender, anemone, and wild oats. What do we know about these ingredients?

  • Black cohosh: Used for a variety of gynecological conditions, black cohosh might have dangerous side effects, and its therapeutic use is not backed by evidence.
  • Wild yam: The first birth control pills were synthesized from a type of Mexican wild yam, and hormonal contraception is known to alleviate menstrual cramps. However, wild yam products are very different from the purified chemicals found in the Pill. There is insufficient evidence for their ability to treat dysmenorrhea.
  • Dong quai: So far, there is insufficient evidence for dong quai’s effectiveness in treating menstrual cramps. There are also concerns that the long-term use of dong quai can be dangerous, as some of its chemicals are known carcinogens.
  • Skullcap: There are hundreds of species in the genus Scutellaria, and the label does not clarify which type is used. A PubMed search does not locate any studies on the effect of skullcap or Scutellaria on menstrual cramps.
  • Silk tassel: I cannot locate silk tassel in a PubMed search for any medicinal use.
  • Lavender: Lavender preparations taken orally may have side effects, and cramp relief is not a known benefit of this herb.
  • Anemone: It is unclear from the label which type of anemone is being used. Of the four types of anemone I located, only one, pulsatilla, is associated with specific claims regarding the relief of menstrual cramps. It is considered to be unsafe when taken orally, as it is a severe irritant. Other types of anemone are considered to be dangerous as well.
  • Wild oats: A PubMed search does not find any evaluation of the use of oats for treating gynecological conditions.

The preparation described above is typical of other herbal remedies, in that evidence of its effectiveness is lacking. More worrying is that some ingredients can have side effects, and their short- or long-term safety is often unknown. Plants have evolved over millions of years to defend themselves with their own powerful pesticides, some of which can exert toxic effects on humans. Herbal remedies are not safe by virtue of their natural origin; in fact, some might cause cancer (aristolochia), increase risk for cardiovascular diseases (ephedra), interfere with prescription drugs like birth control pills and antidepressants (St. John’s wort), cause liver damage (kava), or be unsafe during pregnancy (pennyroyal). Just because something originated from Mother Earth doesn’t mean that it is effective or safe.

Herbal remedies claiming to alleviate cramps might be completely untested for safety or efficacy, and could have risks. Because plants are filled with various chemicals, it is not outside the realm of possibility that some could exert physiological effects on humans. In fact, many of our medicines, such as digoxin, aspirin, and the birth control pill, were originally derived from plants.

Unfortunately, the majority of herbal remedies are currently unevaluated by the scientific method — either for efficacy or safety. I gave up on them a long time ago, after realizing that I didn’t have the information I needed to judge if they were helpful or harmful. They certainly couldn’t hold a candle to more conventional approaches, like birth control pills, nonsteroidal anti‐inflammatory drugs, or even treatment with a heating pad, all of which are backed by evidence and have well-documented side effects — the kind of information that allows the user to make a truly informed decision.