NAC Dosage and Timing: What Owners Report
About this entry (NAC (N-acetylcysteine)): N-acetylcysteine, discussed for rumination, OCD-type thoughts and compulsive habits.
In 14 Reddit owner comments that give an amount, the typical NAC dose was 600 mg (middle half: 600 to 1200 mg). The timing people mention most is at night or before bed (7 comments). These numbers describe what people with stress, anxiety or low mood say they take on Reddit (May 2026 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 |
|---|---|---|---|---|
| mg | 14 | 600 | 600 to 1200 | 600 (10), 1200 (2) |
Counted from amounts written next to the name NAC in 15 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: 600 mg (10), 1200 mg (2).
What studies and NIH sources say
The NIH sets recommended daily amounts only for nutrients, and we have not found an NIH or PubMed source that gives a standard dose for NAC. Product labels vary, so follow the label and ask a pharmacist.
When people take it
| Timing mentioned | Owner comments |
|---|---|
| At night or before bed | 7 |
| In the morning | 4 |
Phrases such as "before bed", "in the morning" or "with food" near the name NAC.
How long it takes, according to owners
| Timeframe mentioned | Comments | Positive | Negative |
|---|---|---|---|
| Within the first week | 3 | 1 | 0 |
| 1 to 4 weeks | 3 | 1 | 2 |
| More than a month | 2 | 2 | 0 |
8 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 Takes time“People often recommend NAC for OCD, but the evidence is more mixed than you might think.”
2/5 Fast-actingStomach upset“It really depends on what you're taking NAC for.”
4/5 Calming effectMood“Interesting framing, though what you are describing as a feature is what pushed me off NAC after about six weeks.”
In their words
3/5 Feeling flat or numbMood“I used to experience this type of anhedonia from NAC for a while when I took 600 mg every day (Doctor's Best, a pretty strong supplement with molybdenum and selen).”
3/5 Feeling flat or numbMood“Turns out all signs point to the long-term NAC use from my understanding (albeit the long period of Accutane probably had some mild effect on me as well).”
4/5“I take NAC mostly for glutathione production, but I also have extreme OCD.”
4/5“Now I use NAC just before bed because it works a little *too* well.”
5/5“NAC works wonders for ruminating thoughts for me.”
1/5 Feeling flat or numbMood“This is so interesting because I have terrible anhedonia the past few months and have been taking 600-1200mg NAC 5-7xweek for nearly a year.”
NAC (N-acetylcysteine) overall: 3.2 from 127 owner comments.
Frequently asked
How much NAC do people take?
In 14 Reddit owner comments that give an amount, the typical NAC dose was 600 mg (middle half: 600 to 1200 mg). That is what people report, not a recommended dose; follow the product label and your doctor's advice.
When do people take NAC?
The timing people mention most is at night or before bed (7 comments). In the morning: 4.
How long does NAC take to work?
8 owner comments mention a timeframe near NAC (for example "after two weeks" or "within an hour"). Within the first week: 3; 1 to 4 weeks: 3; More than a month: 2. Individual experiences vary widely.