Cross-referencing clinical data
A pairing appears on this page only when a trial gave both ingredients together and measured the result. Ephedra has none that clears that bar.
Stitching two separate single-ingredient studies into a pairing is the one thing this engine will not do. When a study of the combination itself holds up at source, it lands here with its citation.
No invented synergy. Where actives were studied on their own rather than together, the record shows each on its own evidence, never a combined effect no trial measured.
Research strength. Research strength says how much work stands behind the combination. It is never a product score.
Independent record. Every finding is cited to a named trial, dated, and never written by the brand.
20 pairings are live across the library today. Checked 20 July 2026.
No study gave these as a pair, so they are not in the card above. But the reason they belong together is settled biochemistry, not a guess, so it is worth knowing.
Ephedrine alkaloids act as indirect sympathomimetics, releasing noradrenaline and stimulating adrenergic receptors. Caffeine antagonises adenosine receptors and inhibits phosphodiesterase, so the cyclic AMP signal that adrenergic stimulation starts is sustained rather than cleared. The two together raise heart rate and blood pressure more than either alone, which is why the combination was historically both popular and the source of reported cardiovascular events. Read this pairing as a caution, not an endorsement.
Green tea catechins inhibit catechol-O-methyltransferase, the enzyme that inactivates noradrenaline. Ephedra alkaloids work by pushing noradrenaline out of nerve terminals. Slowing the clearance of a transmitter while increasing its release stacks two effects on the same adrenergic signal. The practical consequence is a stronger and longer stimulant response, including on heart rate.
Beta-2 adrenergic stimulation activates the sodium-potassium ATPase and shifts potassium from plasma into cells. Ephedrine alkaloids are beta-2 agonists among their other actions, so sustained high intake can lower measured serum potassium. This is a redistribution, not a loss of total body potassium. It matters most for anyone already low or on a potassium-wasting diuretic.
L-theanine raises alpha-wave activity and blunts some of the subjective jitteriness of stimulants. It does not act on adrenergic receptors and does not lower heart rate or blood pressure in any reliable way. Any smoothing of the ephedra experience would be perceptual rather than cardiovascular. Do not read it as a safety measure.
Ephedrine is a weak base excreted largely unchanged by the kidney, and its clearance is strongly pH dependent. Acidifying the urine, as large ascorbic acid doses can, increases the ionised fraction in the tubule and speeds elimination. The same is true in the other direction: alkalinising agents slow clearance and prolong exposure. This is a textbook pharmacokinetic interaction rather than a nutritional one.
Bicarbonate raises urinary pH, which increases the un-ionised fraction of ephedrine available for tubular reabsorption. Less drug leaves in the urine and plasma levels stay higher for longer. Athletes who take bicarbonate for buffering may not realise they are extending a stimulant's half-life. The direction of this effect is well characterised.
Magnesium stabilises cardiac membrane potential and is used clinically in catecholamine-driven rhythm disturbance. Adequate magnesium status is relevant background when adrenergic tone is raised. This is a plausibility argument from physiology, not evidence that magnesium offsets ephedra's cardiovascular load. It should not be presented as a countermeasure.
Nothing specific on file for Ephedra. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.These are the studies our verdict leans on, chosen from the 2 we read for Ephedra. The full linked list is below.
1 source behind our Ephedra verdict: peer-reviewed studies and registered clinical trials. Every one links straight to PubMed, the journal, or ClinicalTrials.gov. Read them yourself.
Evidence surfaced via Semantic Scholar (Allen Institute for AI) and ClinicalTrials.gov. Ranked by study type and citation weight, not cherry-picked.
Read this carefully. These are 653 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Ephedra is, not how risky it is. A report is not proof Ephedra caused anything. It is a signal of what to watch for, nothing more.
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.