Beta-alanine

What it is

Beta-alanine is a non-essential amino acid sold as a sports supplement. In the body it joins with histidine to form carnosine, which is stored in muscle and buffers the acid that builds up during short, hard efforts, so regular intake raises muscle carnosine over time. It is used mainly for physical performance and for holding output through repeated high-intensity work.

A usual adult range, not a national label — the dose and the timing differ by country and by product.

Used for

• Physical performance
• Energy

Approved uses differ by country — some of these may be off-label or unapproved where you live.

What to know while taking it

It is taken with food, and the daily amount is normally split through the day rather than swallowed at once. The usual effect of a large single dose is paraesthesia, a tingling or prickling of the face, neck and hands that begins soon after taking it and fades on its own; it is harmless, and splitting the dose or using a sustained-release form generally prevents it. Nothing here works fast: muscle carnosine accumulates over weeks, so judging the effect after a few days gives no useful answer.

When to see a doctor

Tingling that is painful, one-sided, or persistent rather than brief, or that comes with rash, swelling of the face or lips, or difficulty breathing, is not the expected reaction and is a reason to see a doctor.

Worth knowing

• Tingling skin at higher single doses
• Split the daily dose
• Takes weeks to work