Most people associate L-Lysine with cold sore prevention, but Nutritional Therapist, Sarah Brereton reveals why this essential amino acid does much more.

Many of us are only aware of friends or family taking L-Lysine in connection with cold sore treatment and prevention, but here are some other benefits to be aware of, as it plays a very important role in the body. L-Lysine is an essential amino acid, which means it must be obtained through the diet or supplementation as it cannot be made in the body.

There are many foods rich in lysine – such as protein rich plant and animal-based foods including eggs, lentils, meat, dairy products, and fish – but it can be difficult to obtain enough to correct deficiency symptoms. Lysine is also a precursor to carnitine, another amino acid responsible for converting fatty acids into energy and helping to lower cholesterol. It also aids calcium absorption and promotes collagen formation.

Let’s talk about its main use. L-Lysine may have antiviral effects: it blocks the activity of arginine (another amino acid), which promotes Herpes Simplex Virus (HSV) replication. Therefore, it may help to slow down or prevent the growth of the herpes simplex virus type 1 (HSV-1), which is responsible for cold sores.

It’s impossible to totally avoid foods with arginine – such as beans, seeds, nuts, and lean meats – so taking lysine supplements helps prevent the body from absorbing too much arginine, making it more difficult for HSV-1 to grow and reproduce. This is good news, especially if you are prone to cold sores at certain times, such as when you’re stressed, in the sun, or feeling run down.

For example, sun exposure can trigger a cold sore for some people because the sun’s rays can suppress the immune system, allowing the dormant herpes simplex virus to reactivate. For this reason, many beauticians also recommend taking L-Lysine before laser treatments, especially if you’re susceptible to cold sores.

This is an ideal time of year to top up your levels, with sunnier days on the way. It’s good to know there’s a safe, natural option to help. Some studies show that regularly taking lysine can help prevent cold sore outbreaks. One study even showed that lysine lessens symptoms, reduces
healing time, and prevents cold sores from returning.1

One Nutrition L-Lysine comes in an absorbable form, with easy-to swallow capsules. Just two capsules a day provide 1000mg of L-Lysine. Also, look out for the Pure Fill logo on the side of
One Nutrition packs – it certifies the product is free from excipients, fillers, and additives, which is a really important feature of the One Nutrition range.

If you’re feeling run down, consider taking One Nutrition Revive and Go Vitamin C & Zinc as well.
1. Pedrazini M; L-lysine: Its antagonism with L-arginine in controlling viral infection. British Journal of Pharmacology. Narrative literature review. June 2022