Does Bitter Orange (Synephrine) Help with Weight Loss? Know Science

Does Bitter Orange (Synephrine) Help with Weight Loss Know Science

If you are one of them looking to burn down your excess gains through natural ingredients or food, then you will likely hear about bitter oranges quite frequently. Also scientifically called Citrus aurantium, bitter orange or sour orange is believed to support weight loss and bring down the body composition. While this citrus fruit is known to have a myriad of benefits like skincare and digestive health, or even culinary benefits, how it fairs as a weight loss aid is our point of interest today.

Let’s explore the various scientific studies surrounding bitter orange and body weight to see if there is any weightage on the weight loss claims surrounding this fruit.

Key Points To Note
  • Bitter Orange contains an active compound called synephrine that is believed to support weight reduction.
  • The citrus fruit is often used by supplements given its purported ability to promote lipolysis.
  • Evidence shows that synephrine in bitter orange can contribute to increasing resting metabolism and regulating energy balance.
  • However, there is a lack of concrete studies supporting its impact on overall weight loss, and more extensive research is needed to establish the same.

What Is Bitter Orange (Synephrine)?

What Is Bitter Orange (Synephrine) And Help With Weight Loss

Bitter orange is a citrus fruit that is known to have its roots in Southeast Asia but over time it has spread across southern and western Africa, parts of Europe, and other sub-tropical regions. Also called Seville orange or sour orange, the fruit is extremely bitter and unlike the oranges cannot be consumed wholly. It has a unique reddish-orange look and comes with thick puckered skin. One of the interesting facts about this fruit is that it comes in more than 20 species, the most common of all being Bergamot.

Now bitter orange is believed to have numerous uses. It has been used as a traditional Chinese medicine for centuries for its potential ability to tackle skin and gastrointestinal issues. It is also quite popular in perfumery, and the culinary industry. However, its popularity in the weight loss industry has just grown over the last 20-odd years and its purported weight reduction ability is attributed to an active compound called Synephrine found abundantly in the fruit.

People who advocate it insist that Synephrine is a metabolic enhancer and enzyme activator. It triggers enzymes that contribute to lipid metabolism and glucose regulation leading to an increased energy expenditure and reduced appetite. We will see how science backs up these claims.

Connection Between Bitter Orange (Synephrine) And Weightloss

Connection Between Bitter Orange (Synephrine) And Weightloss

Positive Studies

Exploring the various research papers associated with bitter orange and its potential ability to aid weight loss, We found a few favorable studies that support the claims.

For instance, in one of the recently conducted comprehensive studies about the effects of Synephrine and its compound, researchers demonstrated that regular supplementation of p- p-synephrine led to a significant decrease in blood glucose levels and increased insulin sensitivity. This resulted in increased metabolic rate and fat oxidation due to thermogenesis, preventing weight gain and tackling obesity issues. However, this study was conducted on animal subjects which is worth noting here.

The same study also concluded that synephrine present in bitter orange can significantly influence beige adipocytes which are responsible for firing up energy expenditure thus reducing obesity development.

Meanwhile, We came across another research study from 2018 that supports p-synephrine’s potential to support enzyme activity that is directly associated with carbohydrate metabolism and an increase in ATP levels. An enhanced ATP level increases athletic performance and speeds up the post-workout recovery time which are key to weight loss. This finding is backed by another clinical research from 2021 demonstrating regular supplementation of bitter orange may induce more fat oxidation during workouts when done at low to moderate intensities.

A team of researchers, however, found that while bitter orange (synephrine) has the potential to inhibit glucose production, it doesn’t have any effect on fat accumulation in the liver cells.

Studies With Inconclusive Findings

While the above studies show that bitter orange (synephrine) can have a positive impact on weight loss, there are a few pieces of evidence that speak otherwise or are inconclusive.

One of those studies is a systematic review and meta-analysis conducted by a research team on the safety and efficacy of bitter orange or synephrine. They included a total of 18 articles for the analysis and concluded that long-term use of synephrine in a dose above 20 mg and above can lead to elevated blood pressure and palpitation.

This can pose a threat to heart health and can lead to stroke or other health issues among consumers. Considering the potential risk of long-term synephrine consumption, the French Food Safety Authority (ANSES) concluded that its consumption should be limited to less than 20 mg per day and that it should not be taken along with caffeine to avoid unwanted interaction.

The study was also not able to find any significant beneficial effects on health. There was a minor decrease in body fat but that is statistically insignificant and cannot be taken into consideration.

Safety Aspects Of Bitter Orange (synephrine)

Bitter orange is a natural food and is usually safe for most people unless you are very sensitive. While the majority of the studies in this article are favorable and show that it can have a beneficial effect on weight loss without affecting the body adversely, it is important to stay cautious about some of its side effects. The common ones may include nausea, restlessness, sleeplessness, increased blood pressure, and heart rate which can be caused as a result of high dosage or prolonged use of Bitter Orange (Synephrine).

Several studies have indicated that a dosage between 10 to 20 mg should be ideal although some have used higher doses as well. One of the studies even showed that bitter orange extract (Synephrine) did not have any adverse effect even when used with a dose of 98 mg per day for two months. However, as we have cited a study earlier indicates that a dosage higher than 20 mg may have some side effects on the body. This, however, may be subject to the individual physiological process and the sensitivity of the individual.

Given the varying data, it is best to stay on the minimum doses if you are taking it in the supplement form.


After a detailed walk through the various studies and reviews, it is clear that the data on Bitter orange (Synephrine) and its effect on weight loss is limited. Some of the available studies did establish that the fruit or its compound may increase fat oxidation, and boost resting metabolism and energy expenditure which are key parameters of weight reduction. However, the overall data still stands on mixed perspectives.

That said, shifting to a healthy lifestyle, proper diet, good sleep, and regular exercise are crucial if you are planning on losing those extra gains. Adding more well-researched food and ingredients for weight loss can help accelerate the process. As for bitter orange, it might be a decent addition to your diet provided you do not rely on this alone.