On the hunt for bigger breasts, women on TikTok this summer buzzed over bee pollen: a mixture of plant and flower pollen, as well nectar and bee saliva, that accumulates on the insects’ bodies and is used for honey production. After a handful of content creators suggested it could boost estrogen levels, dozens of women began tossing it in their smoothies and yogurts with the hopes of increasing their cup size. 

Now, about four months after the trend dominated women’s #FYP, videos detailing mild to severe allergic reactions and changes to menstruation, such as heavier bleeding and more painful cramps, are springing up online. These unintended consequences, experts say, serve as a reminder that “natural” isn’t always safe.

“I've seen this over and over again: an influencer with no scientific or medical background speaks to something that they're doing or something they're being paid to talk about, yet none of it is based on science,” said Dr. Allison Rodgers, an OB-GYN and reproductive endocrinologist at Fertility Centers of Illinois.

Bee pollen has been used for centuries as a natural medicine. Ancient Egyptians used to call it a “life-giving dust,” as it contains vitamins, minerals, carbohydrates, polyphenols and other active compounds that have been associated with immune system benefits and even “anti-allergy” properties. Today jars of bee pollen can be bought online for about $25, with most brands recommending a serving size of one teaspoon. 

But studies have yet to analyze how or if bee pollen can affect breast growth or menstruation. 

Janna Kim, 23, decided to try bee pollen to help alleviate “unbearable” symptoms that began after coming off her birth control pill, such as hot flashes and lack of appetite. Kim heard from people on TikTok that the supplement might help, so she gave it a shot. Bigger breasts, Kim said, wasn't what she was after but would be a plus. 

She was adding half a teaspoon of bee pollen to her morning smoothies for a month before experiencing a severe allergic reaction that landed her in the hospital. 

“I was sipping on my smoothie while doing my eyebrows when I noticed my eyes were super glossy and warm,” said Kim, a graduate student and dermatology medical assistant in Arizona. Within minutes, her symptoms progressed and she rushed to the emergency department. “I tried to drink water in the car and it would pool in the back of my closed throat. I started to see stars because I couldn’t breathe.”

Hospital staff admitted Kim right away. It wasn’t long before she began to vomit and was given an epinephrine injection to reverse what doctors told her was an anaphylactic reaction. It came as a shock to Kim, who has never had severe reactions to anything. 

“Nowadays, we’re all leaning away from Western medicine, trying more holistic naturopathic methods to help our bodies, especially women,” said Kim, who didn’t receive any relief from her symptoms while eating bee pollen. “People should just do their research because I thought I was fine for a month, then all of a sudden my body decided to fight back.”

Here’s what science says about bee pollen’s impact on breast growth and menstruation, as well as its role as an allergen. 

Bee pollen can’t make breasts grow

Despite purported success stories, bee pollen cannot help your breasts grow, according to Dr. Allison Rodgers, an OB-GYN and reproductive endocrinologist at Fertility Centers of Illinois. 

Some people on TikTok have said that bee pollen contains phytoestrogens: compounds from plants that mimic estrogen by binding to its receptors like a lock and key. Estrogen is involved in breast growth, so many people have assumed that bee pollen would increase their body’s natural supply of the hormone, thus upping their cup size. 

But research has found that that’s not true. When tested in yeast and human cells, bee pollen did not interact with estrogen receptors.

“Bee pollen is not a phytoestrogen, and unfortunately is not going to be a natural way to increase breast size,” Rodgers said, adding that the only way to naturally grow bigger breasts is to gain weight or get pregnant. Some birth control options could cause a temporary increase in breast size because estrogen can lead to weight gain or fluid retention.

Can bee pollen affect menstruation?

There’s no evidence to support claims that bee pollen can cause changes in menstruation, such as worsening cramps, heavier bleeding, tender breasts, new acne and early or late periods. Similarly, there’s no science that shows bee pollen can alleviate these symptoms.

Ali Velas thinks otherwise. After coming off the birth control pill earlier this year, the 28-year-old from Ohio had no complaints until July when she noticed her period was two weeks late (she wasn’t pregnant). Inspired by other women’s stories, Velas told USA TODAY that she began adding bee pollen to her yogurt every morning. Five days later, her period returned. 

Periods can be irregular for many reasons besides pregnancy, including extreme exercise, stress, obesity, chronic illness, thyroid issues and conditions like polycystic ovary syndrome (PCOS), which occurs when your body produces too much of the male sex hormone androgen. 

Velas was diagnosed with PCOS three years ago, but has been dealing with it since at least 19 years old. The condition could help explain why her period was late, but Rodgers said the probability that bee pollen was responsible for bringing it back is low given there’s no evidence it interacts with estrogen receptors in the body.

“Lots of people have late periods,” Rodgers said. “I don't think we can say that this has any correlation.”

Research published in 2015 in the journal Molecular and Clinical Oncology found that bee pollen mixed with honey helped reduce menopause-type symptoms such as hot flashes, sleep problems and pain during sex. However, the study included only 46 participants, all of whom were breast cancer patients undergoing treatment to lower estrogens’ effects on the body. (Estrogen is known to stimulate breast cancer cell growth.) The placebo treatment — honey alone — produced similar effects as pollen.

Another study published in 2019 in the journal Obstetrics & Gynecology Science found that bee propolis — a sticky compound bees produce by mixing their saliva and beeswax with sap from trees — reduced premenstrual cramps. Many people on social media have referenced this research to support their claims, but bee propolis is not the same as bee pollen.

It’s possible that bee pollen might affect the immune system in a way that influences how uterine lining is shed during menstruation, but Rodgers said that theory has not been studied. 

Bee pollen is a tricky allergen 

You don’t have to be allergic to bees or bee products to experience an allergic reaction to bee pollen, according to Dr. Brian Schroer, pediatric allergist at Cleveland Clinic Children's Hospital.

Pollen from wind-pollinated plants like birch and ragweed, which bees normally don’t visit, sometimes hitchhike on the insects’ bodies as they travel in the air. So if you’re allergic to those or other pollen, you may experience typical seasonal allergy symptoms like itchy eyes, nose and throat after consuming bee pollen. 

It happened to Alexia Erkman, 20, who, after a week of eating half a teaspoon of bee pollen every day, developed chest pain, nasal congestion, headache, sore throat and itchy eyes. She told USA TODAY that it took a week to recover. 

Bee pollen is also no stranger to cross-reactivity: when proteins in one substance are similar to proteins in another, making you sensitive to both, Schroer said. Pollen from ragweed, for example, is known to cross react with pollen from dandelion, which is frequently found in bee pollen. So if you have a ragweed allergy, you could experience an allergic reaction after eating bee pollen.

Schroer said that many people who have pollen allergies aren’t aware they have them because symptoms aren’t bothersome enough to notice. But the risk for anaphylaxis in this case is “very clear” and can happen any time, he said.

Most allergic reactions to bee pollen are likely to occur the first time someone eats it, but in some cases the immune system may need more time to develop a sensitivity to it, Schroer said. 

Dose matters too. “If you eat one teaspoon you might be fine, but if you eat two or three teaspoons, you can experience anaphylaxis,” he said. “Everybody's threshold for reactions are different,” which also depends on factors like whether you recently exercised or drank alcohol.

Schroer suspects that bee pollen allergies may become more common as more people eat it, and he warned that supplements aren’t approved by the FDA for safety and effectiveness before hitting the market — so consume with caution.