An essential amino acid found in meat, dairy and legumes.
Why it’s used: A building block for proteins including collagen.
L-lysine is an essential amino acid, so the body cannot make it and it must come from food. Rich sources include meat, fish, dairy foods, eggs and legumes such as beans and lentils. Most people who eat a varied diet with enough protein get plenty.
Lysine is a building block for proteins throughout the body, including collagen, the most abundant protein in animals and a key structural protein in skin, tendons and bone. Because it is essential, a steady intake from protein foods matters, particularly for people whose diets are low in protein overall.
As a supplement, lysine is usually sold as L-lysine or L-lysine hydrochloride (HCl), in tablets, capsules or powder, with amounts in milligrams (mg). Researchers have studied it in a wide range of human trials, and a 2019 systematic review of 71 studies looked at amounts from under 20mg to 17.5g a day. The side effects reported were mainly stomach-related, such as nausea, stomach ache and diarrhoea. No health claims are authorised for lysine in the UK.
3 findings behind this ingredient. Hover a card for the detail and the source.
A three-month double-blind study gave 40 families in Pakistan lysine-fortified wheat flour and 40 unfortified flour. Children in the lysine group gained more height and weight, and transferrin and immune markers rose in adults and children.
In 88 farm families in northern China, half received wheat flour fortified with 3 g lysine per kg for three months. Children gained more height and weight, adults had higher prealbumin, and several immune markers increased.
A double-blind trial gave 271 men, women and children in Accra, Ghana, 1 g lysine a day or placebo. Lysine reduced diarrhoeal episodes and days ill in children, and days ill in men.
None of our current products contain it. Find the right supplement for you in six questions.
Can't see yours? Ask our team, answered within a working day.
L-lysine is an essential amino acid used to build proteins throughout the body, including collagen in skin, tendons and bone. Because the body cannot make it, it must come from foods such as meat, fish, dairy, eggs and legumes.
A 2019 systematic review of 71 human studies proposed a provisional no-observed-adverse-effect level of 6g a day, based mainly on stomach symptoms. There is no official UK upper level, so stay within the amount on your product label.
Not necessarily. Legumes such as beans and lentils are good plant sources of lysine, so a varied vegan diet that includes them regularly can provide enough. A lysine supplement is optional rather than essential for most people.
Information only, not medical advice. If you take medication, are pregnant or breastfeeding, speak to your GP or pharmacist first.
Answer six quick questions and we will point you to the protocol or product that fits your goal. No email needed.
