AMINO ACIDS
Glycine (L-Glycine)
Glycine is a calming amino acid that supports restful sleep and collagen production.
Also known as: L-glycine, amino acid glycine
At a glance
- Form
- L-Glycine
- Category
- Amino Acids
- In an apiece formula
- 3,000 mg a day (you can change it)
- Recommended intake
- No recommended intake (not an essential nutrient)
- Upper limit
- No established UL
- Studied for
- Relaxation, Skin health*
- Reference
- NIH ODS: Dietary Supplements, What You Need to Know
What the research says
3 g of glycine at bedtime reduced next-day tiredness after short sleep in a placebo-controlled trial.*
randomized placebo-controlled trial · Bannai M, Front Neurol 2012. Read the study on PubMed
Who should be careful
Our safety rules leave glycine out of a formula, or keep the amount lower, with:
Life stage
- Pregnancy
- Breastfeeding
- Trying to conceive
Always check with your doctor or pharmacist before adding a supplement if you take medication, are pregnant or nursing, or have a health condition. Stay under the upper limit from all sources combined, including multivitamins.
Symptoms it’s studied for
- Tired or low energy
- Afternoon crash
- Brain fog or poor focus
- Poor sleep
- Anxious or stressed
- Joint aches or stiffness
- Catching every cold
- Hot flashes or night sweats
- Low libido
- Sugar cravings
From the Journal
- Which supplements help you sleep? What the research shows
Magnesium, L-theanine, melatonin, saffron, glycine and tart cherry: what the trials found, the doses studied, and when poor sleep is a reason to see a doctor instead.
Questions
How much glycine a day?
apiece formulas usually include 3,000 mg a day. The recommended intake for adults is No recommended intake (not an essential nutrient). Upper limit: No established UL.
What is glycine used for?
Glycine is a calming amino acid that supports restful sleep and collagen production. In apiece it is part of formulas for Relaxation, Skin health.*
Who should be careful with glycine?
apiece’s safety rules leave it out or limit it with: Pregnancy; Breastfeeding; Trying to conceive. Check with your doctor or pharmacist if any apply to you.
Can I get glycine in a personalized supplement?
Yes. apiece builds one daily blend around your goals and, if you have them, your lab results. Glycine can be part of it at the amount listed, with every ingredient shown and never more than 10 capsules a day.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This page is general information, not medical advice. Check with your doctor or pharmacist before starting a supplement, especially if you take medication, are pregnant or nursing, or have a health condition. Updated 2026-10-21.