None of the 6 anxiety studies on this page used magnesium glycinate, and the 2 trials that compared magnesium alone with a placebo found no difference on anxiety scores. The largest magnesium-only result, 4.5 points on the GAD-7 anxiety scale, came from an open-label trial with no placebo.
What the anxiety studies measured
The 6 anxiety studies below, published 2000 to 2021, enrolled 44 to 264 people each and used oxide, chloride, sulfate or a salt the abstract does not name. One is a re-analysis of another, and none of the 6 used glycinate.
A 2017 trial in 99 postpartum women (33 per group) measured anxiety and depression scores after a 320 mg magnesium sulfate tablet a day for 8 weeks: state anxiety (p = .995) and trait anxiety (p = .234) did not differ from placebo.
A 2000 crossover trial in 44 women with premenstrual symptoms measured anxiety-related symptoms after 200 mg of magnesium (as oxide) for one cycle: the four arms showed no overall difference. In a predefined comparison, magnesium with 50 mg of vitamin B6 scored lower (p = 0.040), an effect the authors called modest.
A 2017 open-label trial in 126 adults with mild-to-moderate depression measured anxiety on the GAD-7 after 248 mg of magnesium a day (as chloride) for 6 weeks: scores fell 4.5 points more than during 6 weeks without it. There was no placebo, and 112 people gave usable data.
| Year · journal · PMID | People | Salt and dose | Length | Measured | Result | Limitation |
|---|---|---|---|---|---|---|
| 2017 · Women Health · 27617502 | 99 postpartum women, 33 per group | Sulfate, one 320 mg tablet a day | 8 weeks | State and trait anxiety, depression | No difference from placebo | Abstract does not say whether 320 mg is salt or magnesium |
| 2000 · J Womens Health Gend Based Med · 10746516 | 44 women with premenstrual symptoms | Oxide, 200 mg magnesium, with and without 50 mg B6 | 1 cycle per arm, crossover | Anxiety-related symptom diary | Magnesium alone: no overall difference; with B6: lower (p = 0.040) | One cycle; authors note poor absorption from oxide |
| 2017 · PLoS One · 28654669 | 126 adults with depression | Chloride, 248 mg magnesium a day | 6 weeks vs 6 weeks without | GAD-7 anxiety, PHQ-9 depression | GAD-7 −4.5 points (CI −6.6 to −2.4) | Open-label, no placebo; enrolled for depression |
| 2018 · PLoS One · 30562392 | 264 stressed adults with low blood magnesium | 300 mg a day with or without 30 mg B6; salt not named | 8 weeks | DASS-42 stress score | Fell 44.9% and 42.4%; arms did not differ | No placebo arm; Sanofi employees among authors |
| 2021 · Stress Health · 33864354 | Same trial, re-analysed | Same as 2018 | 8 weeks | DASS-42 anxiety, quality of life | Anxiety scores fell from baseline in both arms | Post-hoc; no placebo |
| 2004 · Curr Med Res Opin · 14741074 | 264 adults with mild-to-moderate anxiety | Hawthorn, California poppy and magnesium; dose not in abstract | 3 months | Hamilton anxiety scale | −10.6 vs −8.9 on placebo (p = 0.005) | Three ingredients; magnesium's share unknown |
| 2025 · Nat Sci Sleep · 40918053 | 155 adults with poor sleep | Bisglycinate, 250 mg magnesium a day | Primary result at 4 weeks | Insomnia score plus other psychological questionnaires | Other psychological outcomes did not differ | A sleep trial; abstract does not name the questionnaires |
| 2017 · Nutrients · 28445426 | Review of 18 studies | Varied | Varied | Self-reported anxiety | Positive in 4 of 8 anxious samples and 4 of 7 premenstrual samples; none postpartum | Authors rate the evidence quality poor |
| 2024 · Cureus · 38817505 | Review of 15 trials, 7 on anxiety | Varied | Varied | Self-reported anxiety | 5 of 7 reported lower scores | Small samples; both null trials premenstrual or postpartum |
Arithmetic: the trial doses as glycinate
Matching the 300 mg dose of the largest magnesium trial with glycinate takes 2,128–2,536 mg of the salt, or 3–4 size 00 capsules, and brings about 1.9 g of glycine. Glycinate is 11.8–14.1% magnesium by weight, depending on bound water.
| Trial dose | Salt used | Weight of that salt | Same magnesium as glycinate | Size 00 capsules | Glycine |
|---|---|---|---|---|---|
| 200 mg | Oxide | 332 mg | 1,418–1,691 mg | 2–3 | 1.2 g |
| 248 mg | Chloride | 971–2,074 mg | 1,759–2,096 mg | 3 | 1.5 g |
| 300 mg | Not named | Not computable | 2,128–2,536 mg | 3–4 | 1.9 g |
The postpartum trial gave one 320 mg magnesium sulfate tablet a day. If 320 mg is the weight of the salt, the tablet carried 32–65 mg of magnesium, because sulfate is 9.9–20.2% magnesium depending on bound water. The abstract does not say which. No trial on this page measured glycine for anxiety.
On the shelf, 73 of 126 on-market NIH DSLD labels that name glycinate name it as the only magnesium salt, and 14 also name magnesium oxide (snapshot 2026-08-10). A label that mixes in oxide carries less glycine for the same magnesium.
Best magnesium glycinate for anxiety, by measurement
Within glycinate, the cheapest ranked label is Amazon Elements Chelated Magnesium 270 mg at $0.0666 per 100 mg of magnesium, against a median of $0.1889 across 17 ranked offers (prices observed 2026-10-26 to 2026-11-02). "Best" names a measurement here, not an anxiety result.
| Measurement | Label | Number |
|---|---|---|
| Lowest price per 100 mg, within glycinate | Amazon Elements Chelated Magnesium 270 mg | $0.0666; $4.00 for 30 days at 200 mg |
| Lowest price with no oxide or other salt named | Amazon Elements Chelated Magnesium 270 mg | $0.0666 per 100 mg |
| Fewest capsules or tablets for 200 mg | Amazon Elements Chelated Magnesium 270 mg | 2 a day |
Prices are compared only within glycinate; the chloride page covers the salt from the open-label trial.
Safety
The upper limit for magnesium from supplements is 350 mg a day for adults, set in 1997 and listed by the NIH Office of Dietary Supplements; food magnesium does not count toward it. In the 2018 trial, 12.1% of people on magnesium with B6 and 17.4% on magnesium alone had side effects possibly linked to it. Talk to a clinician if anxiety gets in the way of daily life, if you take medicines for mood, or if you have kidney disease.