Glycine · Glycine
Cheap amino acid with better sleep and glutathione-precursor benefits.
Short answer
Glycine (Glycine) is a amino acid / glutathione support with evidence grade B, meaning it is supported by human RCTs. We track 8 produkter containing Glycine. Typical doses range from 300.0 to 3000 mg per portion. The top-ranked product scores 8.3 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $99.00 per månad.
Top Glycine produkter
| Product | Varumärke | Dose | Pris/mo | 3rd-party tested | Poäng |
|---|---|---|---|---|---|
| Glycine Powder | 3000 mg | $20.00 | Yes | 8.3 | |
| Longevity Mix - Blood Orange | 2000 mg | $49.00 | Yes | 6.5 | |
| AGZ: Nightly Sleep Support | 2000 mg | $99.00 | Yes | 6.5 | |
| Glycine Supplement | 1000.0 mg | $19.95 | Yes | 6.4 | |
| Daily Longevity Blend | 700 mg | $69.00 | Yes | 6.4 |
Scores are editorial judgments, not a scientific standard. Se how we score.
What it is
The simplest amino acid, sweet-tasting, found in bone broth and collagen. Your body uses it to make glutathione (your main antioxidant), collagen, and creatine.
Why people take it
Small trials show 3 g at bedtime improves sleep quality and next-day alertness. Combined with NAC (see GlyNAC), it restores glutathione levels in older adults and improves multiple aging markers.
Our verdict
One of the most underrated supplements. Extremely cheap, extremely safe, real benefits in sleep and glutathione status.
Structure & class
Simplest amino acid, α-carbon with H side chain. Precursor to glutathione (with cysteine and glutamate).
Mechanism & clinical data
Kumar et al. 2021 (Clin Transl Med) demonstrated GlyNAC (glycine + NAC) restores glutathione and improves multiple biomarkers of aging. Bannai 2012 showed 3 g pre-sleep improved sleep quality.
Pharmacokinetics
~1 hour.
Dose & forms
What to watch out for
None major. Very sweet in powder form, mix in water or coffee.
Säkerhet limits and interactions
When a product exceeds the UL or contains an ingredient with clinically significant interactions, a "Review advised" flag appears on its product page and links here.
Where this dose comes from
The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.
When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.
Regelverk status
Timeline
Regelverk events, evidence grade changes, and key research milestones for Glycine, most recent first. Every entry links to its primär source.
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EU Court sharpens the bar for botanical health claimsA Court of Justice of the European Union ruling in april 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
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EU report identifies 117 supplement substances as potential health risksThe HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
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Kumar et al. 2021 (Clin Transl Med)GlyNAC for 24 weeks restored glutathione and improved oxidative stress markers in older adults.
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EU Health Claims Regulation adoptedRegulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
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EU introduces the Novel Food RegulationRegulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 maj 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
Glycine is an amino acid that lowers core body temperature to aid sleep onset and, paired with NAC, restores glutathione levels lost with age.
Verified 2026-07-05. We update this section as new peer-reviewed trials land.
Best-supported claim
Glycine's most consistently replicated human effect is improving subjective sleep quality when taken before bed. Multiple small randomized, dubbelblind, placebokontrollerad crossover trials from the same Japanese research group found 3 g of glycine 30 minutes before bedtime improved subjective sleep quality, reduced sleep onset latency, and improved next-day fatigue and alertness, with effects appearing on the first night without tolerance developing over the study period (https://pmc.ncbi.nlm.nih.gov/articles/PMC3328957/). A 2024 GeroScience systematisk översikt confirmed the sleep signal but flagged small sample sizes and high risk of bias, noting no independently replicated, adequately powered trial has been published. Combined with N-acetylcysteine as GlyNAC, glycine has stronger backing: a Baylor College of Medicine randomized clinical trial in 24 older adults over 16 weeks found GlyNAC corrected glutathione deficiency, lowered oxidative stress and inflammation, and improved gait speed, muscle strength, and six-minute walk distance versus placebo (https://pubmed.ncbi.nlm.nih.gov/35975308/).
Not supported by the evidence base
Marketers often present glycine alone as an anti-aging or longevity compound based on the GlyNAC aging-reversal headlines, but nearly all of the dramatic aging-hallmark results (mitochondrial function, telomere-related markers, cellular senescence markers) come from the glycine-plus-NAC combination, not glycine by itself. A separate 114-person RCT testing glycine and NAC at three doses in healthy older adults found the combination did not significantly increase the primär glutathione endpoint in the study population as a whole, only in a subgroup with high baseline oxidative stress and low baseline glutathione (https://pubmed.ncbi.nlm.nih.gov/35821844/). For metabolic health, marketing claims often cite glycine's association with lower diabetes and heart disease risk in observational data as if it were proven causal and clinically actionable; an evidence review by Evidentia Nutrition states plainly that current interventional evidence does not support clinical use of glycine alone for glycaemic control, and that small trials showing HbA1c or fasting glucose improvements have not been replicated at scale.
Typical dose
3 g before bedtime for sleep; 5-15 g/day (often split into 3 doses) studied for metabolic outcomes
Säkerhet
Glycine is generally recognized as safe by the FDA and has been well tolerated in trials up to 15 g/day, with psychiatric studies using up to 0.8 g/kg/day over 6-12 weeks without serious adverse events. GlyNAC combination trials in older adults reported no adverse events over 16 weeks (https://pubmed.ncbi.nlm.nih.gov/35975308/). Long-term safety beyond about 4-6 months has not been established in controlled human trials.
Interactions worth flagging
- clozapine (may reduce effectiveness)
Three recent studies to know
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Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical TrialLäs studie →
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A Randomized Controlled Clinical Trial in Healthy Older Adults to Determine Efficacy of Glycine and N-Acetylcysteine Supplementation on Glutathione Redox Status and Oxidative DamageLäs studie →
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Metabolic impact of dietary glycine supplementation in individuals with severe obesityLäs studie →
Landmark studies
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Kumar et al. 2021 (Clin Transl Med)
GlyNAC for 24 weeks restored glutathione and improved oxidative stress markers in older adults.
Läs studie →
Found in these produkter (8)
Alla produkter in our catalog that contain Glycine, ranked by our overall score. Ranking is editorial, never paid.
Buying guides and comparisons
Related ingredients
Se alla in Amino acid / Glutathione support →Molekyler in the same class, plus the actives most often formulated alongside Glycine in our catalogue.
Frequently asked questions
What is Glycine?
The simplest amino acid, sweet-tasting, found in bone broth and collagen. Your body uses it to make glutathione (your main antioxidant), collagen, and creatine.
What dose of Glycine should I take?
The trial dose in published human studies is 3000 mg per dag, with a range of 1000 to 10000 mg per dag. Always consult a qualified clinician before starting any supplement.
Is Glycine safe?
None major. Very sweet in powder form, mix in water or coffee.
What is the best Glycine supplement?
We track 8 produkter containing Glycine. The top-ranked product scores 8.3 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.
What is the evidence grade for Glycine?
Glycine has evidence grade B, meaning it is supported by human RCTs. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.
Data verification
Bevisning grades are reviewed when new human RCTs are published. Product counts update automatically as new produkter are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.