stimulantEVIDENCEBUSOTC

Synephrine (Bitter Orange)

aka Citrus aurantium · Bitter orange

Citrus aurantium alkaloid. Alternative to ephedrine for fat loss. Cardiovascular load is real; effective dose narrow.

Dose range25–100mg

Half-life—h

Onset—min

Safety3/5medium evidence base

Mechanism of action

Selective beta-3 adrenergic agonist with some beta-1 and beta-2 activity. Promotes lipolysis and thermogenesis similarly to ephedrine but at lower potency and with less central stimulation. Cardiovascular load is real — increased heart rate and blood pressure are dose-related.

History

Synephrine became popular after the 2004 FDA ban on ephedra-containing supplements. It was marketed as a 'safer ephedrine' but evidence supports modest efficacy with real cardiovascular load. The compound is unscheduled but routinely banned by athletic and military testing programs. Quality of products varies; many supplements contain higher doses than claimed.

Benefits

Weight loss (modest)
EVIDENCEB
Multiple RCTs.
Athletic performance (acute)
EVIDENCEC
Multiple small trials.

Side effects

Tachycardiacommonmoderate
Hypertensioncommonmoderate
Anxietycommonmoderate

Cited research

Synephrine for body composition: meta-analysis (Stohs)2011
PMID 21649450 ↗
Bitter orange safety review (Stohs)2012
PMID 23154274 ↗

Where to buy

Affiliate links

Ad Affiliate links — we may earn a commission at no extra cost to you.

Vendor	Product	Size	Price	Per unit
Nootropics DepotFeatured 4.8	Synephrine (Bitter Orange) — Nootropics Depot	—	See vendor	—	Shop Ad
Double Wood Supplements 4.4	Synephrine (Bitter Orange) — Double Wood	—	See vendor	—	Shop Ad
Amazon Marketplace 3.5	Synephrine (Bitter Orange) — Amazon	—	See vendor	—	Shop Ad

Community reviews

0 approved

No approved reviews yet. Be the first.

Share your experience

Reviews require disclosed dose, duration, and conflict of interest. Posted after editorial review.