Cross-referencing clinical data
A pairing appears on this page only when a trial gave both ingredients together and measured the result. Quinine 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.
Quinine reduces the excitability of the motor end plate and lengthens the refractory period of muscle fibre, which is the pharmacological reason it was historically taken for night-time muscle cramping. Magnesium acts at the neuromuscular junction by a different route. Taken together the effects point the same direction on paper. Regulators in several countries have restricted quinine for cramping because of blood disorder reports, so this pairing is documented history rather than a current recommendation.
Quinine alters calcium movement in muscle fibre, which is part of how it changes contraction and relaxation timing. The source index flags calcium co-occurrence as antagonistic rather than cooperative. That means the relationship is one to be aware of, not one to build a formula around. The direction and size of any effect at supplement-level intakes has not been characterised.
Quinine and its stereoisomer quinidine block potassium channels and prolong cardiac repolarisation, which is well documented pharmacology and the reason quinidine was used as an antiarrhythmic. The co-occurrence index flags potassium as antagonistic. Anyone taking potassium alongside a quinine-containing product should regard the combination as a cardiac electrophysiology question for a clinician. This is a caution, not a synergy.
Cinchona bark preparations contain condensed tannins alongside the alkaloids, and polyphenol binding of non-haem iron in the intestinal lumen is settled nutrition chemistry. A bitter bark tonic taken with a meal will reduce iron uptake from that meal. Purified quinine salts do not carry this liability because the tannins are removed. The distinction between bark and isolated alkaloid matters here.
Quinine is a reference agonist in bitter taste receptor research and activates TAS2R subtypes at low concentration. Bitter receptor stimulation is the classical mechanism behind aperitif bitters and gastric secretion. Enzyme preparations act further down the same digestive sequence by supplying hydrolytic capacity directly. The pairing is mechanistically coherent, and quinine at food-flavouring levels is the only intake relevant to it.
Nothing specific on file for Quinine. 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 1 we read for Quinine. The full linked list is below.
12 sources behind our Quinine 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 32,921 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Quinine is, not how risky it is. A report is not proof Quinine 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.