Synephrine information

synephrine powder citrus aurantium

Synephrine is currently one of the best supplements available to promote weight loss. This supplement can not only help to promote weight loss, but it can also function as an energy booster. These effects are possible since this supplement has a similar structure to ephedrine. However, synephrine does not have the potentially harmful effects [1]. That’s why this supplement is gaining popularity as a fat burner and pre-workout ingredient.

Synephrine is also known as:
Bitter orange extract
Citrus Aurantium
Synephrine HCL

Functions of synephrine

Improved fat burning, energy and sports performance
Most people use synephrine because it is able to improve sports performance, increase fat burning and provide more energy [1][2][4][5]. Research has now established that it can promote energy and metabolism, without increasing blood pressure or heart rate [1][2][4][5]. It has also been shown that a single dose of 50mg can improve our metabolism for approximately 75 minutes [1]. According to the research, this results in the burning of approximately 65 extra calories [1]. In addition, other studies have reported that synephrine can increase our energy and fat burning by promoting lipolysis [2][5]. This means that more fat is burned to provide our body with extra energy. Synephrine may also slightly increase the thermal effect of food [15]. This means that more calories are used to burn our consumed food. However, this claim requires further investigation, since this effect has only been proven in women [15].

Helps with stubborn fat cells
Synephrine can also help get rid of stubborn fat cells [16]. This can make it easier to reduce fat in certain areas, such as the abdomen, hips, and thighs. This is possible because synephrine can block the activity of alpha receptors in fat cells [16]. These alpha receptors hinder the mobilization of fat cells, making the relevant fat cells more difficult to burn. However, synephrine can thus help mobilize these fat cells by blocking the alpha receptors [16].

Other functions
In addition to increasing metabolism, it can also lower our insulin resistance [2][5]. This is important because a high insulin level prevents fat from being broken down for energy. In addition, this is important as excess insulin is eventually stored in our body as fat. Lastly, this supplement can act as an appetite suppressant [17]. The appetite suppressant effect may function due to various mechanisms, but the exact way this works is not clear yet [16]. Some researchers argue that the appetite suppression is possible due to the antioxidant and / or anti-inflammatory effects of synephrine [18][19]. However, this needs to be studied further.

Who can use synephrine ?

Synephrine users mainly consume it to improve metabolism and reduce appetite. Users want these effects as they aid in fat loss and weight management. It is also used by people who want a small increase in energy without increasing their blood pressure or heart rate.

How should I use synephrine ? / Dosages

Based on current knowledge and research, dosages of 25mg are recommended. This supplement should be used ~15-30 minutes before a workout. On rest days, it can be used during the day. You can also choose to consume two doses of 12.5mg during the day. However, this supplement should not be taken before bedtime, as its energy-enhancing effects can interfere with sleep quality.

How does this supplement work ?

Synephrine stimulates specific adrenergic receptors in our body. This provides most of the positive effects of this supplement. However, this supplement only stimulates beta-3 adrenergic receptors, without affecting other receptors. This allows it to provide the desired effects without negative side effects normally associated with compounds that stimulate other adrenergic receptors [20].

Stacking / combining

Synephrine can be combined with various other supplements. For example, it can be combined with creatine, BCAAs and pre-workout supplements. Many people choose to combine it with caffeine. This is not surprising as research indicates that this combination may further enhance the fat burning properties of both supplements [21][22]. In addition, it can also be combined well with naringin and hesperidin. These are other active substances that are present in the bitter orange fruit (Citrus aurantium). Current research indicates that this combination may also further enhance the metabolic boost [1].

Where does synephrine come from ?

Synephrine has been used in China for many years and first appeared in Europe around 1920. It is a naturally occurring substance which can be found in citrus fruits, and especially in the bitter orange fruit [2][3]. However, it is also made synthetically. Fortunately, this has no effect on the quality or operation of this product.

Safety & competitive use

Several studies have shown that this supplement is effective and safe when used at normal dosages [1][4][5][6][7][8][9][10][11][12][13][14][15][17][21][22]. Current studies also indicate that this supplement does not negatively affect blood pressure or heart rate at normal doses [1][4][5][6][8][10][11][12][14][15][17][21][22]. However, in combination with caffeine or in extreme amounts, it can potentially result in a temporary increase in blood pressure and / or heart rate [6].

Competitive use
Synephrine is currently legal in almost every country. But despite its safety, it may be banned by some sports federations for its beneficial effects. If you participate in professional sports competitions, it is advised to ask the relevant sports association whether this product can be used.

Correct use
A dietary supplement can contribute to a healthy and active lifestyle. However, it should not be a substitute for a healthy lifestyle and a varied diet. The recommended dosage should not be exceeded, since side effects may occur otherwise. Temporary side effects of synephrine can include: higher heart rate, higher blood pressure and headaches. In rare cases, these side effects can also occur with normal doses. If side effects occur, consumption should be discontinued.

As with any supplement, we advise users to consult a physician before use. In particular if you use medication or have health complaints. This product should not be used by people which have high blood pressure or heart problems. In addition, this supplement should not be used by women who are pregnant or breastfeeding. Furthermore, this product should not be used by persons under 18 years of age and must be kept out of the reach of children. Keep this product in a cool and dry place to maintain the quality.


  1. Stohs, S. J., Preuss, H. G., Keith, S. C., Keith, P. L., Miller, H., & Kaats, G. R. (2011). Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes. International journal of medical sciences, 8(4), 295.
  2. Haaz, S., Fontaine, K. R., Cutter, G., Limdi, N., Perumean‐Chaney, S., & Allison, D. B. (2006). Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update. Obesity reviews, 7(1), 79-88.
  3. Lasch, F. (1927). Über die Pharmakologie des Sympathols, einer neuen adrenalinähnlichen Substanz.(Zugleich ein Beitrag zur Frage der chemischen Konstitution und pharmakodynamischen Wirkung). Naunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie, 124(3), 231-244.
  4. Stohs, S. J. (2017). Safety, efficacy, and mechanistic studies regarding Citrus aurantium (bitter orange) extract and p‐synephrine. Phytotherapy Research, 31(10), 1463-1474.
  5. Ratamess, N. A., Bush, J. A., Kang, J., Kraemer, W. J., Stohs, S. J., Nocera, V. G., … & Faigenbaum, A. D. (2015). The effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performance. Journal of the International Society of Sports Nutrition, 12(1), 35.
  6. Sawler, S. (2011). Synephrine , Octopamine and Caffeine Health Risk Assessment ( HRA ) Report.
  7. Lynch, B. (2013). Review of the safety of p-synephrine and caffeine. Intertek-Cantox Report, 1-20.
  8. Kaats, G. R., Miller, H., Preuss, H. G., & Stohs, S. J. (2013). A 60 day double-blind, placebo-controlled safety study involving Citrus aurantium (bitter orange) extract. Food and Chemical Toxicology, 55, 358-362.
  9. Ratamess, N. A., Bush, J. A., Kang, J., Kraemer, W. J., Stohs, S. J., Nocera, V. G., … & Faigenbaum, A. D. (2015). The effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performance. Journal of the International Society of Sports Nutrition, 12(1), 35.
  10. Shara, M., Stohs, S. J., & Mukattash, T. L. (2016). Cardiovascular safety of oral p‐synephrine (bitter orange) in healthy subjects: a randomized placebo‐controlled cross‐over clinical trial. Phytotherapy research, 30(5), 842-847.
  11. Shara, M., Stohs, S. J., & Smadi, M. M. (2017). Safety evaluation of bitter orange (p‐synephrine) extract following oral administration for 15 days to healthy human subjects a clinical trial. Submitted for publication.
  12. Stohs, S. J., & Shara, M. (2013). Review of the safety and efficacy of bitter orange (Citrus aurantium) and its primary protoalkaloid, p-synephrine, in weight management.
  13. Gutiérrez‐Hellín, J., & Del Coso, J. (2016). Acute p‐synephrine ingestion increases fat oxidation rate during exercise. British journal of clinical pharmacology, 82(2), 362-368.
  14. Jung, Y. P., Earnest, C. P., Koozehchian, M., Galvan, E., Dalton, R., Walker, D., … & Kreider, R. B. (2017). Effects of acute ingestion of a pre-workout dietary supplement with and without p-synephrine on resting energy expenditure, cognitive function and exercise performance. Journal of the International Society of Sports Nutrition, 14(1), 3.
  15. Gougeon, R., Harrigan, K., Tremblay, J. F., Hedrei, P., Lamarche, M., & Morais, J. A. (2005). Increase in the thermic effect of food in women by adrenergic amines extracted from Citrus aurantium. Obesity research13(7), 1187-1194.
  16. Brown, C. M., McGrath, J. C., Midgley, J. M., Muir, A. G. B., O’Brien, J. W., Thonoor, C. M., … & Wilson, V. G. (1988). Activities of octopamine and synephrine stereoisomers on α‐adrenoceptors. British journal of pharmacology93(2), 417-429.
  17. Kaats, G. R., Leckie, R. B., Mrvichin, N., & Stohs, S. J. (2017). Increased eating control and energy levels associated with consumption of bitter orange (p-synephrine) extract: a randomized placebo-controlled study. Nutrition and Dietary Supplements9, 29-35.
  18. Arbo, M. D., Schmitt, G. C., Limberger, M. F., Charão, M. F., Moro, Â. M., Ribeiro, G. L., … & Limberger, R. P. (2009). Subchronic toxicity of Citrus aurantium L.(Rutaceae) extract and p-synephrine in mice. Regulatory Toxicology and Pharmacology54(2), 114-117.
  19. Kang, S. R., Han, D. Y., Park, K. I., Park, H. S., Cho, Y. B., Lee, H. J., … & Kim, G. S. (2011). Suppressive effect on lipopolysaccharide-induced proinflammatory mediators by Citrus aurantium L. in macrophage RAW 264.7 cells via NF-B signal pathway. Evidence-Based Complementary and Alternative Medicine2011.
  20. Carpéné, C., Galitzky, J., Fontana, E., Atgié, C., Lafontan, M., & Berlan, M. (1999). Selective activation of β3-adrenoceptors by octopamine: comparative studies in mammalian fat cells. Naunyn-Schmiedeberg’s archives of pharmacology359(4), 310-321.
  21. Seifert, J. G., Nelson, A., Devonish, J., Burke, E. R., & Stohs, S. J. (2011). Effect of acute administration of an herbal preparation on blood pressure and heart rate in humans. International journal of medical sciences8(3), 192.
  22. Stohs, S. J., & Ratamess, N. A. (2017). Effects of p-synephrine in combination with caffeine: a review. Nutrition and Dietary Supplements9, 87-96.


Mario Klasens Author XBR