Compound or practice · Supplement
Synephrine
The 'bitter orange' stimulant that replaced ephedra — mild thermogenic effect, real cardiovascular caution.
- Overall grade
- Grade C
- Last revised
- 1
- graded outcome
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
1 at grade C — 1 graded row
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- Metabolic rate / fat lossEvidence grade C
Usually with caffeine
Smallmixed
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Thin evidence: Metabolic rate / fat loss (grade C).
- Caution with Caffeine: Additive cardiovascular stimulation in fat-burner stacks.
- Watch with Caffeine: Additive cardiovascular stimulation in fat-burner stacks.
Interactions
Documented pairings with supplements and medicines. A medicine on this list is a conversation for whoever prescribes it.
CaffeineCaution
Additive cardiovascular stimulation in fat-burner stacks.
The evidence in words
What it is
Synephrine is a stimulant alkaloid from bitter orange (Citrus aurantium), common in fat-burner formulas.
How it works
It has mild adrenergic (fat-mobilizing, thermogenic) activity, weaker than ephedrine.
What the evidence shows
Small increases in metabolic rate and modest fat-loss signals, usually studied with caffeine. It raises heart rate and blood pressure, and stacking it with caffeine and other stimulants (as fat-burners do) compounds the cardiovascular load.
Safety & interactions
Raises heart rate/blood pressure; caution with stimulants, heart conditions, and before exercise. Caffeine — Additive cardiovascular stimulation in fat-burner stacks.
Bottom line
A mild thermogenic with a real stimulant footprint. Modest at best; treat stacked fat-burners with caution.
Related reading
Entries that share this one's tags or conditions.
- Capsaicin / CapsimaxChili heat with a small, real thermogenic and appetite effect — and a genuine topical pain use.Evidence grade C
- Synephrine for Metabolic rate / fat lossEvidence grade C — Usually with caffeineEvidence grade C
- Synephrine: side effects, safety & interactionsRaises heart rate/blood pressure; caution with stimulants, heart conditions, and before exercise.Evidence grade C
- YohimbineA fasted-cardio fat-loss aid and erectile-function agent — effective but genuinely anxiogenic and blood-pressure-raising.Evidence grade C
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.