Amino Acids, Heart Disease and Blood Pressure: Arginine, Citrulline, Taurine, Glycine and Carnitine

Urgent first

Sudden chest pain that does not go away, pain spreading to the arm, neck, jaw, stomach or back, or chest pain with sweating, sickness, light-headedness or breathlessness could be a heart attack. The UK NHS says to call 999 straight away and not to drive yourself to A&E. [1] In the US, call 911.

Start here

This page is information only. High blood pressure and heart disease are managed with a clinician. The NHS says a GP will usually prescribe blood pressure medicine if blood pressure is very high, if there is higher risk of heart attack or stroke, or if it stays high after lifestyle changes. [1] Do not replace or stop a prescribed medicine for an amino acid product. Tell your pharmacist and doctor about every supplement; see Medication Interactions.

How to read the evidence on this page

We label findings as "surrogate" (blood pressure or cholesterol readings), "clinical outcome" (heart attacks, deaths, hospital stays), "mixed", "limited" (small or few trials), "evidence of harm" and "Proper evidence not found". A lower blood pressure number in a short trial does not prove fewer heart attacks. "Study amount" means the dose a trial used, never advice.

Where each amino acid sits

Classification matters. MedlinePlus lists arginine and glycine among the conditionally essential amino acids (usually not essential, except in times of illness and stress). [2] A 2023 review of upper intake levels calls arginine nonessential and citrulline nonproteinogenic (not used to build proteins). [3] A 2026 review describes taurine as a non-proteinogenic amino acid. [4] We did not find a classification source for carnitine among the pages read for this page. Each compound has its own page: Arginine and Citrulline, Taurine, Carnitine and Glycine.

Evidence table

What the table does and does not show

• Blood pressure drops are surrogate findings. The arginine and citrulline meta-analyses measured blood pressure, and the trials were small, short and varied in dose. The arginine meta-analysis also reported similar results in trials where participants did not use blood pressure medicines. [5]
• Where a clinical outcome was tested, the arginine result was a warning. The post-heart-attack trial concluded that L-arginine should not be recommended after acute myocardial infarction. [7]
• Carnitine has a separate safety question. Gut bacteria turn dietary carnitine into trimethylamine, which the liver converts to TMAO, and a review discussed whether this might raise cardiovascular risk, alongside benefits for metabolism. [15] The review presents this as a postulated concern, so evidence is unsettled; see L-Carnitine for Heart, Fertility, Exercise and Weight.
• Evidence for taurine comes from people with liver or metabolic disease and short trials; see Taurine, Energy Drinks, Heart Health and Longevity.

For the focused arginine and citrulline summary see Arginine, Citrulline, Nitric Oxide and Blood Pressure.

Related

Amino Acids & Protein · Protein Foundations