Vietnamese tea, brewed in Nigeria

Polyphenols that neutralise free radicals and slow the oxidation of LDL cholesterol. This is what sits behind the antioxidant claim.

Theanine crosses into the brain and raises alpha-wave activity, smoothing the edge off the leaf's caffeine. That pairing, not the absence of caffeine, is why the alertness feels calm rather than jittery.

Mildly raise thermogenesis and fat oxidation. The effect is real but small, on the order of a few percent of daily energy use.

Support nitric-oxide-driven relaxation of vessel walls and reduce cholesterol absorption in the gut, which is the proposed route for the modest blood-pressure and cholesterol effects seen in regular drinkers.

Free-radical scavenging polyphenols behind the antioxidant and immune-support claim.

Old wild trees push more amino acids into the bud, which is why this leaf tastes sweeter and thicker than plantation tea. Theanine is also what produces the settled, focused alertness alongside the caffeine.

The clean-energy effect. Buffered by the high theanine, but present. This is not a caffeine-free tea.

The floral aroma and honey-golden liquor. Sensory rather than physiological.

Stimulate bile flow from the liver and gallbladder, which aids fat digestion. This is the actual basis for the liver-support and detox claim. It is the strongest-evidenced herb in the blend.

Mild sedative and gut-soothing action; also the main source of the blend's natural sweetness and body.

Zeaxanthin concentrates in the retina and is the reason goji is linked to eyesight; the polysaccharides are the studied immune-modulating fraction.

Anti-inflammatory flavonoids plus aromatic compounds with mild calming activity, giving the traditional cooling and headache effect.

Fifty times sweeter than sugar and anti-inflammatory on the stomach lining. It is also the ingredient that needs watching, see the note below.

Sweetness with no sugar and no effect on blood glucose, which is why the blend suits people avoiding sugar.

The signature compound of this plant. In laboratory work it inhibits alpha-glucosidase, the gut enzyme that breaks starch into glucose. Slowing that enzyme blunts the sugar spike after a starchy meal, which is exactly why Vietnamese families drink it after eating, and the mechanism behind the blood-sugar claim.

Mildly astringent and antibacterial in the gut, including against organisms involved in indigestion. This underlies the traditional use for bloating and appetite.

The earthy aroma, and a mild carminative effect that helps trapped gas move.

The main alkaloid, and the reason this tea works at all. In animal studies it has sedative activity on the central nervous system and relaxes vascular smooth muscle. One compound drives both the sleep claim and the blood-pressure claim.

Related alkaloids with antiarrhythmic and vessel-relaxing effects; they contribute the calming-the-heart element of the traditional description.

The pronounced bitterness is the active fraction, not a fault. A weak, sweet-tasting brew is a weak dose.

Act on the hypothalamic-pituitary-adrenal stress axis. This is the driver of the reduced-fatigue and mental-focus claims, and the best-studied part of the blend.

Cordycepin is an adenosine analogue studied for improving how efficiently tissues use oxygen; the polysaccharides are the immune-modulating fraction. Together these carry the energy and lung claims.

Stimulate macrophage and natural-killer-cell activity in laboratory models, the specific basis for the immune-system claim, rather than a general tonic effect.

Zeaxanthin accumulates in the retina, which is where the eyesight claim comes from. The polysaccharides add antioxidant capacity.

Mildly calming and gut-soothing, and the source of the blend's sweetness and body.

The most concrete part of the blood claim: mulberry supplies actual iron, and its vitamin C content improves how much of that iron the body absorbs. The anthocyanins are the deep purple antioxidants.

Aromatic compounds with mild antispasmodic activity on smooth muscle, the traditional route for easing menstrual cramping, plus the polyphenols behind the skin claim.

Long used as a blood tonic in Vietnamese and Chinese practice; the polysaccharides show mild immune and anti-fatigue activity in animal models.

Traditionally the calming and sleep-supporting element of this pairing; also adds sweetness.

Antioxidant load supporting the skin claim, and the same retinal zeaxanthin as above.

Chrysin binds the benzodiazepine site on the GABA-A receptor, the same receptor family that prescription sedatives act on, far more gently. This is the actual mechanism behind the sleep and anxiety claims, and passionflower has some human trial support for mild insomnia.

Adds central sedative activity through a separate pathway, which is why the two are combined rather than used alone.

Spinosin acts on serotonin 5-HT1A signalling to shorten the time it takes to fall asleep. Jujube seed is the classical insomnia herb in this tradition, and it is doing real work here.

The organic acids stimulate gastric enzyme and bile secretion, which is how it breaks down a heavy, fatty meal. This is the core of the digestion and bad-fats claim. The procyanidins also act on the heart, which is why the caution below matters.

Sorbitol draws water into the bowel as a mild osmotic laxative. This is the most direct mechanism for relieving a full, heavy belly.

Mild antispasmodic on the gut wall, easing cramping and trapped gas.

Anti-inflammatory on the stomach lining (a licorice extract is a recognised remedy for indigestion) and the source of the blend's sweetness. Also the ingredient with the clearest downside.