{ "presentation": "complete-card", "format_version": 3, "overview": "Glycine is an amino acid your body makes and gets from food. People take it before bed hoping to fall asleep more easily and feel more rested the next day. Early studies suggest it may help, but the evidence is limited.", "overview_sources": "Sleep Foundation · 2026", "overview_source_ids": [ "self-guide-glycine-sleep-foundation" ], "sections": [ { "role": "explanation", "title": "Understanding glycine at bedtime", "items": [ { "label": "Why bedtime?", "text": "Glycine helps nerve cells communicate. One proposed sleep effect is helping the body release heat as it settles for sleep. That cooling mechanism comes mainly from animal research; it is not a proven explanation for every person’s response.", "source": "Kawai et al. · 2015", "source_ids": [ "self-guide-glycine-kawai-2015" ] }, { "label": "The amount studied is usually 3 g.", "text": "Small human studies used 3 grams, generally 30–60 minutes before bed. This describes the research, rather than an established dose that works for everyone.", "source": "GeroScience review · 2023", "source_ids": [ "self-two-glycine-review-2023" ] }, { "label": "Powder and capsules contain the same amino acid.", "text": "Plain powder tastes sweet and can be mixed into water. Compare the actual glycine per serving: 3 g is 3,000 mg, and a scoop of protein powder is not the same amount of glycine.", "source": "Sleep Foundation · 2026", "source_ids": [ "self-guide-glycine-sleep-foundation" ] }, { "label": "Magnesium glycinate is a different supplement.", "text": "It combines magnesium with glycine. A magnesium dose on that label is not a dose of plain glycine, even though the names sound similar.", "source": "Sleep Foundation · 2026", "source_ids": [ "self-guide-glycine-sleep-foundation" ] } ] }, { "role": "benefits", "title": "Potential benefits", "items": [ { "label": "Falling asleep sooner.", "text": "A small sleep-lab study found shorter time to falling asleep and reaching deep sleep. It did not show an increase in the share of sleep spent in REM or deep sleep.", "source": "Yamadera et al. · 2007", "source_ids": [ "self-rebuild-glycine-yamadera-2007" ] }, { "label": "Feeling better rested.", "text": "Participants also rated their sleep more positively and reported spending a greater share of their time in bed asleep. These were short studies with few people.", "source": "Yamadera et al. · 2007", "source_ids": [ "self-rebuild-glycine-yamadera-2007" ] }, { "label": "Less next-day fatigue.", "text": "A short study after reduced sleep found less tiredness on the first day, but not the third. Glycine has not been shown to replace the need for enough sleep.", "source": "Bannai et al. · 2012", "source_ids": [ "self-guide-glycine-bannai-2012" ] } ] }, { "role": "cautions", "title": "Good to know", "items": [ { "label": "More can upset the stomach.", "text": "Higher amounts can cause nausea. Brief sleep trials do not establish the safety or benefit of taking it nightly for years.", "source": "Sleep Foundation · 2026", "source_ids": [ "self-guide-glycine-sleep-foundation" ] }, { "label": "Pregnancy, breastfeeding or medicines need a check.", "text": "A clinician or pharmacist can review whether adding a supplement fits your situation.", "source": "NIH ODS · accessed 2026", "source_ids": [ "self-two-ods-supplement-safety" ] }, { "label": "Snoring and gasping need their own attention.", "text": "Loud snoring, pauses in breathing or marked daytime sleepiness can signal sleep apnea and warrant assessment.", "source": "NHLBI · 2025", "source_ids": [ "self-complete-nhlbi-apnea-2025" ] } ] }, { "role": "community", "title": "From community discussion", "intro": "Individual experiences show the range of responses, not how likely a benefit is.", "items": [ { "label": "Falling asleep and staying asleep can differ.", "text": "One poster found glycine mainly helped them fall asleep. Another reported fewer early awakenings with 3 g plus magnesium; that combination cannot show what glycine did alone.", "source": "Community · r/Supplements", "source_ids": [ "self-two-glycine-onset-maintenance" ] }, { "label": "Some report vivid dreams or worse sleep.", "text": "Alongside positive accounts, replies describe unusually vivid dreams, waking too early or insomnia after taking glycine.", "source": "Community · r/Supplements", "source_ids": [ "self-search-glycine-reddit-2026" ] }, { "label": "Some report no benefit after months of use.", "text": "A Longecity user noticed no sleep change after a couple of months taking about 3 g before bed.", "source": "Community · Longecity", "source_ids": [ "self-search-glycine-longecity-2015" ] }, { "label": "Heavier sleep can come with difficult mornings.", "text": "One user adding 3 g to magnesium described vivid dreams and oversleeping. In a later reply, they thought excessive training was their biggest issue, so the cause remained uncertain.", "source": "Community · r/Supplements", "source_ids": [ "self-two-glycine-mornings" ] }, { "label": "Taste and convenience influence the form.", "text": "People describe bulk powder as inexpensive; capsules avoid the taste and are easier for travel.", "source": "Community", "provenance": "preserved-community-record" }, { "label": "Higher amounts bring stomach complaints in some reports.", "text": "Accounts of 10 g experiments include digestive discomfort. They do not establish better sleep than the smaller amounts studied.", "source": "Community", "provenance": "preserved-community-record" }, { "label": "People compare a week or two of similar nights.", "text": "Some compare nights off or stop after no benefit or heavy mornings. Caffeine, alcohol, scrolling and a changing sleep schedule complicate the comparison, especially with shift work or caregiving.", "source": "Community", "provenance": "preserved-community-record" }, { "label": "Sleep stacks make the result harder to untangle.", "text": "Posts pair glycine with theanine or melatonin. An improvement with several ingredients does not identify which one helped.", "source": "Community · r/Supplements", "source_ids": [ "self-search-glycine-reddit-2026" ] } ], "groups": [ { "title": "Falling asleep, staying asleep and the next morning", "item_indices": [ 0, 1, 2, 3 ] }, { "title": "Taste, amounts and stomach comfort", "item_indices": [ 4, 5 ] }, { "title": "Comparing nights and sleep stacks", "item_indices": [ 6, 7 ] } ] } ], "related": [ "magnesium-night", "sleep-hours", "cool-bedroom", "cbt-i", "screens-before-bed" ] }