Taurine and Blood Pressure: What the Prehypertension Trial Actually Found

Taurine has had a long second life as a cardiovascular supplement, distinct from its energy-drink reputation. The relevant signal is modest but specific: a randomised, placebo-controlled trial in adults with prehypertension reported a meaningful drop in clinic and ambulatory blood pressure after 12 weeks of taurine 1.6 g per day. The finding is not new in animals — it sits on top of decades of work in spontaneously hypertensive rats — but it is the most rigorous human evidence to date.

Trial design and findings

120 adults with prehypertension (systolic 120–139 or diastolic 80–89 mm Hg) were randomised to taurine 1.6 g daily or placebo for 12 weeks [1]. Clinic systolic BP fell by an average of 7.2 mm Hg with taurine versus 2.6 mm Hg with placebo. Diastolic fell 4.7 vs 1.3 mm Hg. Twenty-four-hour ambulatory BP, the more reliable endpoint, also dropped — by about 3.8 systolic and 3.5 diastolic mm Hg net of placebo [1]. Vasodilator function improved on flow-mediated dilation testing.

Plausible mechanism

Plasma hydrogen sulfide (H₂S) — an endogenous vasodilator gas — rose during taurine treatment, and the BP change correlated with the H₂S change in mediation analysis [1]. Animal work supports a pathway in which taurine inhibits TRP-3 channel-mediated calcium influx in vascular smooth muscle. This is a coherent story but, as always, the human data establish the effect more than the mechanism.

How this compares to other dietary BP interventions

A 3–4 mm Hg reduction in ambulatory systolic BP is in the same range as cutting sodium intake by about 1 gram daily, increasing potassium by 1.5 g/day, or modest weight loss [2]. The DASH diet typically yields 5–11 mm Hg in untreated stage-1 hypertension. A first-line antihypertensive drug at standard dose yields 8–12 mm Hg. Taurine sits between dietary changes and pharmacotherapy in effect size and is not a substitute for either when BP is clearly elevated.

Safety and dose

EFSA's 2009 review concluded that chronic intakes up to 6 g/day are well tolerated in adults; the 1.6 g/day trial dose is well below that threshold [3]. Adverse events in the prehypertension trial were comparable between groups. Taurine is normally cleared renally; people with severe kidney disease and those on specific neurological medications (lithium, some antiepileptics) should discuss any amino-acid supplement with their clinician before starting.

What the trial did not show

The trial was 12 weeks. There is no long-term outcome data on cardiovascular events with taurine supplementation. The participants were prehypertensive — already-treated hypertensive patients were not studied. Whether the effect persists, attenuates, or grows with longer use is unknown. A 2024 meta-analysis of several smaller trials supports the direction of effect but pooled estimates are heterogeneous [4].

Bottom line

Taurine 1.6 g/day for 12 weeks reduced clinic and ambulatory blood pressure by a clinically modest, dietarily-meaningful amount in prehypertensive adults. It is not a replacement for first-line lifestyle interventions or for medication when indicated, but it is among the better-tested amino acid options for cardiovascular support, and is generally well tolerated. Anyone using taurine for blood pressure should still monitor BP and pursue dietary and weight measures concurrently.

Who is most likely to benefit and how to monitor

The subgroup with the largest effect in the prehypertension trial was participants in the high-normal range (systolic 130–139). For someone with home readings in that band who is already pursuing dietary sodium reduction, weight management, and aerobic activity, taurine 1.6 g/day for 12 weeks is a low-risk empirical addition. The reasonable monitoring approach is twice-daily home BP readings for the week before starting and the last week of the trial, looking for a mean reduction of more than 3 mm Hg. If no benefit is seen, discontinue. If benefit is seen, continue with periodic reassessment, because the long-term durability of effect is uncertain. Taurine should not be used to defer indicated antihypertensive medication when BP is established above 140/90 or in patients with cardiovascular disease, diabetes, or chronic kidney disease where guideline targets are lower.