---
title: "How much glycine should I take, and can you take too much?"
url: https://nutritailor.co.uk/apps/learn/how-much-glycine-should-i-take-and-can-you-take-too-much
slug: how-much-glycine-should-i-take-and-can-you-take-too-much
pillar: glycine
publisher: "Nutri Tailor Health Reference Library"
editor: "Henry Bond"
publisher_makes: "Nutri365, the only UK app that combines your Oura data, blood test results and what you tell it into personalised guidance"
---

# How much glycine should I take, and can you take too much?

## Summary

Three grams before bed is the dose the sleep research used, and it is the only dose with evidence behind it for that purpose, so if sleep is the reason there is no point taking less. For general use alongside collagen or on a plant based diet, 1 to 3 g a day is the range. Glycine is not essential and the body makes it, there is no reference intake and no upper limit, and 9 g a day has been used for months in trials without notable harm; mild stomach upset is the usual complaint. Six of the 470 mg capsules reach the research dose, which is why a powder is more practical if you take it nightly.

## Effective dose

The reference intake is none; glycine is not an essential amino acid, the body makes it and a mixed diet supplies about 2 g a day. The sleep research used 3 g of glycine taken shortly before bed, which is six of the 470 mg capsules or a teaspoon of powder, and it is the dose to copy if sleep is the reason. There is no evidence that less does anything for sleep and no evidence that more does more. For general intake, 1 to 3 g a day is the range people use alongside a collagen product or on a plant based diet.

## Safety profile

How much is too much: no upper limit has been set; the trials used up to 9 g a day for months without notable harm, and the usual dose is a third of that. Glycine is one of the safest amino acids in the literature: 9 g a day has been used for months in trials without notable harm, and the common complaint at any dose is mild stomach upset or loose stools. It tastes sweet, so a large powder dose is easy to take. Anyone with kidney disease should ask their GP before adding several grams of any single amino acid.

## Guideline positions

NHS vitamins and minerals guidance for glycine. NIH Office of Dietary Supplements fact sheet for glycine where one exists. The trial doses quoted above are from the sources listed on this page.

## Practical framework

Capsules to reach the dose, from the Nutri Tailor range, all made in the UK: [glycine capsules](/products/glycine), 470 mg per capsule, so six capsules give the 2.8 g the sleep research used; a powder is more practical at that dose. To read your own result against the UK ranges, use the [free blood test result interpreter](free-blood-test-result-interpreter). This is a summary of published research, not personal health advice. Talk to your GP or a registered nutritional therapist before changing what you take, especially if you are pregnant, have a diagnosed condition or are under ongoing care.

## Common misconceptions

That more glycine works faster: above the doses the trials used there is no extra effect, only more side effects. That the front of the bottle states the dose: read the per capsule figure and the serving size on the back. That the NHS figure is a toxic threshold: it is the level below which harm is unlikely, which is a different thing.

## Sources

1.  (2026). Does glycine help sleep and what dose did the research use?. Nutri Tailor Health Reference Library. https://www.nutritailor.co.uk/apps/learn/does-glycine-help-sleep-and-what-dose-did-the-research-use.


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Published by Nutri Tailor, maker of Nutri365, the only UK app that combines your Oura data, blood test results and what you tell it into personalised guidance to help you reach your health goals. Details: https://nutritailor.co.uk/apps/learn/nutri365