L-glutamine Dosage and Timing: What Owners Report
In 37 Reddit owner comments that give an amount, the typical L-glutamine dose was 6 g (middle half: 5 to 10 g). The timing people mention most is in the morning (36 comments). These numbers describe what people with IBS say they take on Reddit (November 2025 to October 2026); they are not dosing advice. Follow the label and ask a doctor or pharmacist, especially if you take medicines.
Amounts owners mention
| Unit | Comments | Typical (median) | Middle half | Most-mentioned amounts |
|---|---|---|---|---|
| g | 37 | 6 | 5 to 10 | 5 (13), 10 (8), 15 (4) |
| mg | 7 | 500 | 5 to 1000 | 5 (2) |
| scoops | 3 | 1 | 1 to 2 | 1 (2) |
Counted from amounts written next to the name L-glutamine in 49 owner comments (a comment can give more than one amount). Products differ in strength, so a number of capsules or scoops is not comparable between brands. Most-mentioned: 5 g (13), 10 g (8), 15 g (4).
What studies and NIH sources say
- A 2019 placebo-controlled trial in adults with IBS that began after a gut infection used 5 g of glutamine three times a day for 8 weeks.[PubMed]
When people take it
| Timing mentioned | Owner comments |
|---|---|
| In the morning | 36 |
| On an empty stomach | 28 |
| At night or before bed | 17 |
| Split into two doses | 9 |
| With or after food | 9 |
Phrases such as "before bed", "in the morning" or "with food" near the name L-glutamine.
How long it takes, according to owners
| Timeframe mentioned | Comments | Positive | Negative |
|---|---|---|---|
| Minutes to hours | 3 | 1 | 0 |
| Within the first week | 1 | 1 | 0 |
| 1 to 4 weeks | 10 | 5 | 2 |
| More than a month | 5 | 3 | 0 |
18 owner comments mention a timeframe such as "after 2 weeks", "within an hour" or "it took a month". A timeframe can describe when someone noticed a change or how long they tried it before giving up, so read it as a rough signal.
4/5 Bloating & gas“So the first time I took L-glutamine I was on a low fodamap diet but still bloating while eating anything.”
4/5“L-glutamine has been an absolute miracle supplement for me, I take 5 G morning and 5 G night both on an empty stomach and then don't eat for at least an hour, I also take a vitamin with active B6 so it can convert the glutamine into GABA...”
4/5“I saw a post here not long ago about the same symptoms and the girl said she started taking L Glutamine and all symptoms disappeared.”
In their words
4/5“My condition improved when I started to take Glutamine in the morning and one banana before bed.”
3/5 Side effects“Almost same what I’ve faced, what I can tell you that you have to be very careful of what you are eating, try Low FODMAP, it worked for me doing low fodmap diet for 3 months and taking magnesium glycinate daily at night + glutamine 5 g…”
3/5 Bloating & gasSide effects“It's complicated we knew nothing on the microbiome a few years before it's so complex that i don't think we can be specialist of it as we still doesn't know enough yet, yes of course as i have gastritis post h pylori i take glutamine 15 g…”
5/5“I drink a glass of 5g L-Glutamine and one teaspoon of Psyllium seed husks every morning on an empty stomach and it has been lifechanging.”
4/5“The other product I have used that does seem to help calm the gut down after the elemental etc is something call GI Reset - it has Glutamine a month many other herbs.”
5/5“The game changer for me was L-glutamine.”
L-glutamine overall: 4.0 from 456 owner comments.
Frequently asked
How much L-glutamine do people take?
In 37 Reddit owner comments that give an amount, the typical L-glutamine dose was 6 g (middle half: 5 to 10 g). That is what people report, not a recommended dose; follow the product label and your doctor's advice.
When do people take L-glutamine?
The timing people mention most is in the morning (36 comments). On an empty stomach: 28; At night or before bed: 17.
How long does L-glutamine take to work?
18 owner comments mention a timeframe near L-glutamine (for example "after two weeks" or "within an hour"). Minutes to hours: 3; Within the first week: 1; 1 to 4 weeks: 10; More than a month: 5. Individual experiences vary widely.