Many people want a magic pill to boost energy and promote weight loss.
The plant ephedra gained popularity as a possible candidate in the 1990s and became a common ingredient in dietary supplements until the mid-2000s.
While some studies showed it could boost metabolism and weight loss, safety concerns were noted as well.
This article tells you what you need to know about ephedra’s effects on weight loss, as well as its potential dangers and legal status.
Ephedra sinica, also called ma huang, is a plant native to Asia, though it also grows in other areas around the world. It’s been used in Chinese medicine for thousands of years (, ).
While the plant contains multiple chemical compounds, the major effects of ephedra are likely caused by the molecule ephedrine ().
Ephedrine exerts multiple effects within your body, such as increasing metabolic rate and fat burning (, ).
For these reasons, ephedrine has been studied for its ability to reduce body weight and body fat. In the past, it gained substantial popularity in weight loss supplements.
However, due to safety concerns, supplements containing specific types of compounds found in ephedra — called ephedrine alkaloids — have been banned in several countries, including the United States ().
Summary The plant ephedra (ma huang) contains multiple chemical compounds, but the most notable is ephedrine. This molecule impacts several bodily processes and was used as a popular dietary supplement ingredient prior to being banned in several countries.
Much of the studies examining the effects of ephedra on weight loss occurred between the 1980s and early 2000s — before supplements containing ephedrine were banned.
Although multiple components of ephedra may impact your body, the most notable effects are likely due to ephedrine.
Several studies showed that ephedrine increases resting metabolic rate — the number of calories your body burns at rest — which may be due to an increase in the number of calories burned by your muscles (, ).
Ephedrine can also boost the fat-burning process in your body (, ).
One study found that the number of calories burned over 24 hours was 3.6% greater when healthy adults took ephedrine compared to when they took a placebo ().
Another study observed that when obese individuals went on a very-low-calorie diet, their metabolic rate dropped. However, this was partially prevented by taking ephedrine ().
In addition to the short-term changes in metabolism, some studies show that ephedrine can promote weight and fat loss over longer time periods.
However, long-term data on the usefulness of ephedrine for weight loss is lacking ().
Additionally, many ephedrine studies examine the combination of ephedrine and caffeine rather than ephedrine alone (11).
Summary Ephedrine, a major component of ephedra, can increase the number of calories your body burns. Research has shown this results in greater weight and fat loss over weeks to months, though long-term studies are limited.
Many studies examining the weight loss effects of ephedrine have combined this ingredient with caffeine.
The combination of ephedrine and caffeine appears to exert greater effects on your body than either ingredient alone (, ).
For example, ephedrine plus caffeine increases metabolic rate more than ephedrine alone ().
In one study in healthy overweight and obese adults, the combination of 70 mg of caffeine and 24 mg of ephedra increased the metabolic rate by 8% over 2 hours, compared to placebo ().
Some research has even reported that caffeine and ephedrine individually had no effects on weight loss, while the combination of the two did produce weight loss ().
Over 12 weeks, ingesting a combination of ephedra and caffeine 3 times per day led to a reduction of 7.9% of body fat as compared to only 1.9% with a placebo ().
Another 6-month study in 167 overweight and obese people compared a supplement containing ephedrine and caffeine to a placebo during a weight loss program ().
The group taking ephedrine lost 9.5 pounds (4.3 kg) of fat compared to the placebo group, which only lost 5.9 pounds (2.7 kg) of fat.
The ephedrine group also decreased body weight and LDL (bad) cholesterol more than the placebo group.
Overall, the available evidence indicates that ephedrine-containing products — particularly when paired with caffeine — may increase weight and fat loss.
Summary Ephedrine plus caffeine may increase metabolic rate and fat loss more than either ingredient alone. Studies show the combination of ephedrine and caffeine produces greater weight and fat loss than a placebo.
Doses of ephedrine used in research vary, with intakes of less than 20 mg per day considered low, 40–90 mg daily considered moderate, and doses of 100–150 mg per day considered high.
Although some positive effects on metabolism and body weight have been seen across a variety of doses, many have questioned the safety of ephedrine.
Individual studies have shown mixed results regarding the safety and side effects of this substance across a variety of doses.
Some have reported no significant side effects, while others indicate a variety of side effects that even caused participants to withdraw from the studies (, , ).
In-depth reports have combined the results of multiple studies to better understand concerns associated with ephedrine consumption.
One analysis of 52 different clinical trials found no serious adverse events such as death or heart attack in studies on ephedrine — with or without caffeine (11).
Yet, the same analysis found these products were associated with a two- to threefold increased risk of nausea, vomiting, heart palpitations, and psychiatric problems.
Additionally, when individual cases were examined, several deaths, heart attacks, and psychiatric episodes were potentially linked to ephedra (11).
Based on the evidence, potential safety concerns were significant enough to prompt legal action in the United States and elsewhere ().
Summary While some individual studies did not demonstrate serious side effects of ephedra or ephedrine consumption, mild to highly concerning side effects became apparent upon examination of all available research.
While the ephedra herb and products like ma huang tea are available for purchase, dietary supplements containing ephedrine alkaloids are not.
Due to safety concerns, the Food and Drug Administration (FDA) banned products containing ephedrine in 2004 (, 19).
Some ephedrine-containing medications are still available over the counter, though regulations on the purchase of these products can vary by state.
Due to the substantial popularity of ephedrine-containing products prior to the FDA’s ban, some individuals still try to find weight loss products with this ingredient.
For this reason, some dietary supplement manufacturers will market weight loss products that contain other compounds found in ephedra, but not ephedrine alkaloids.
These products may not have the safety concerns observed for products containing ephedrine — but they may also be less effective.
While some countries outside of the United States have also banned ephedrine-containing products, the specific regulations vary.
Summary Dietary supplements containing ephedrine alkaloids were banned by the FDA in 2004. Medications containing ephedrine and the ephedra plant are still available for purchase, though regulations may vary by location.
The plant ephedra has long been used in Asian medicine.
Ephedrine, one of the main components in ephedra, can boost metabolism and cause weight loss — especially in combination with caffeine.
Still, due to safety concerns, dietary supplements containing ephedrine — but not necessarily other compounds in ephedra — are currently banned in the United States and elsewhere.