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Bitter orange a.k.a. P-synephrine or Citrus Aurantium comes from a tree native to Asia. The peel, flower, leaf, fruit, and fruit juice are used to make extracts for medicinal/clinical purposes – including pre workouts.

Bitter orange contains the active ingredient P-Synephrine which is a molecule similar to ephedrine but less potent. P-Synephrine/bitter orange is primarily used as a fat burner or cognitive enhancer in pre workout products. P-Synephrine (P-hydroxy-α-{methylaminomethyl}benzylalcohol) is a protoalkaloid compound and trace amine that is endogenously produced in the human body. This means that it is found in the body even if it is not supplemented.

What are the clinical doses?

Recommended doses vary on timing. For acute doses, the recommended amount is 50mg, however, when dosing multiple times in a day, amounts of 10-20mg up to 3x a day have been used. P-synephrine shows synergism with caffeine which is more pronounced in naïve caffeine users

IS it banned by WADA?

The metabolite of synephrine – octopamine is a banned specified stimulant by WADA and is banned in competition (WADA prohibited substances 2021).

Synephrine, however, is allowed by WADA (although it is included in their 2021 monitoring program). Supplementation of synephrine has been reported to not significantly increase urinary octopamine whereas supplementation of octopamine itself does increase urine concentrations of octopamine. Due to this, it seems that bitter orange is on the cards again for offseason use!

What does it do?

P-synephrine is a beta-agonist compound similar to ephedrine – as such, it can increase metabolic rate through increasing lipolysis and basal metabolic rate. These effects are generally independent of diet, and can exert an increase in basal metabolic rate to produce weight loss over an extended period of time.

TLDR – doses of 50mg p-synephrine worth of bitter orange have been shown to increase basal metabolic rate and contribute towards weight loss. Whilst bitter orange itself isn’t banned by WADA, its active ingredient P-synephrine is on their 2021 Monitoring Program and its metabolite octopamine is a banned stimulant in competition. Taking bitter orange or P-synephrine has been shown to not increase octopamine concentration in urine but do with that information what you like!


Haaz, S., Fontaine, K.R., Cutter, G., Limdi, N., Perumean‐Chaney, S. and Allison, D.B., 2006. Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update. Obesity reviews, 7(1), pp.79-88.

Stohs, S.J., Preuss, H.G., Keith, S.C., Keith, P.L., Miller, H. and 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), p.295.

Thevis, M., Koch, A., Sigmund, G., Thomas, A. and Schänzer, W., 2012. Analysis of octopamine in human doping control samples. Biomedical Chromatography, 26(5), pp.610-615.

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