Activated Charcoal
Summary
Activated charcoal binds many substances in the gut, including medicines. Small 1980s trials found less gas and bloating, and EU regulators allow a flatulence claim at 1 g before and 1 g after a meal (grade D). Later work found no effect on fecal gases. High doses lowered cholesterol in tiny old studies. It reduces absorption of oral drugs.
Key facts
- Lowered breath hydrogen and bloating vs placebo in a 99-person double-blind trial and fewer flatus events in a 1981 trial[1][2]
- Authorised claim: reduces excessive flatulence after eating, with 1 g at least 30 minutes before and 1 g shortly after the meal[4][5]
- 2.08 g/day for a week did not reduce fecal sulfur gases or total gas in 5 volunteers[3]
- Given 2 hours after rivaroxaban, it cut exposure by 43% (29% when given at 8 hours)[10]
- 16–24 g/day lowered LDL 29–41% in studies of 7–10 patients; a 1988 double-blind trial reported no effect[6][7][8]
- 5 graded human outcomes on this page
- October 13, 2026
How it works
EstablishedActivation creates a very large porous surface that adsorbs molecules in the gut so they pass out in the stool instead of being absorbed. It binds many drugs taken by mouth; its binding capacity for gut gases may be used up during transit.[3][7][11]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Dyspepsia | Grade C | Improved | RCT · n = 132 · 2009 | 1 row |
| Gas and bloating | Grade D | Improved | RCT · n = 99 · 1986 | 2 rows |
| Cholesterol | Grade D | Improved | Crossover RCT · n = 10 · 1989 | 2 rows |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Dyspepsia symptoms (charcoal plus simethicone) | Improved | Grade C | RCT · n = 132 · 2009 Adults with dyspepsia seen in general practice (France) Form: Combination: activated charcoal and simethicone (Carbosylane) · Dose: Dose not stated in the abstract · Duration: 3 months More patients improved by at least two points than with placebo (P=0.043); abdominal fullness, bloating and slow digestion eased. | 19349130 (opens PubMed)Source [9] |
| Colonic gas (breath hydrogen) and bloating after lactulose | Improved | Grade D | RCT · n = 99 · 1986 Adults in the USA (n=30) and India (n=69) Form: Activated charcoal · Dose: Dose not stated in the abstract · Duration: Single test sessions Compared with placebo, charcoal lowered breath hydrogen and reduced bloating and cramps in both groups (P<0.05). | 3521259 (opens PubMed)Source [1] |
| Total and LDL cholesterol vs cholestyramine and bran | Improved | Grade D | Crossover RCT · n = 10 · 1989 Patients with severe hypercholesterolaemia (Finland) Form: Activated charcoal · Dose: 16 g/day (dose-response arm: 4–32 g/day) · Duration: 3 weeks per phase 16 g/day lowered total cholesterol 23% and LDL 29%, against 31% and 39% for cholestyramine 16 g. Vitamins A, E and 25(OH)D did not change. | 2612535 (opens PubMed)Source [7] |
| Total and LDL cholesterol in high cholesterol | Improved | Grade D | Open-label trial · n = 7 · 1986 Patients with hypercholesterolaemia (Finland) Form: Activated charcoal · Dose: 8 g three times daily (24 g/day) · Duration: 4 weeks Total cholesterol fell 25% and LDL cholesterol 41%; HDL rose 8%. Side effects were negligible. | 2874369 (opens PubMed)Source [6] |
| Fecal sulfur gases, total gas and symptoms | No effect | Grade D | Open-label trial · n = 5 · 1999 Healthy volunteers (USA) Form: Activated charcoal · Dose: 0.52 g four times daily (2.08 g/day) · Duration: 1 week No significant reduction in sulfur-containing gases, total fecal gas or abdominal symptoms; lab tests suggested charcoal becomes saturated in the gut. | 9934757 (opens PubMed)Source [3] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Activated charcoal capsules or tablets | Varies[1][6] | Not absorbed; it acts inside the gut.[3][11] | Side effects were negligible at 24 g/day in a 4-week cholesterol study; vitamins A, E and D levels did not change at 16 g/day.[6][7] | Gas, bloating and cholesterol studies |
| Charcoal plus simethicone combinations | Varies[9] | Not absorbed; acts inside the gut.[9] | Studied for 3 months in general practice with symptom improvement over placebo.[9] | Dyspepsia |
Studied doses
Doses studied in human trials ranged from 2.08 g/day (0.52 g four times daily) for gas up to 4–32 g/day for 3–4 weeks in cholesterol studies. The EU flatulence claim is based on 1 g before and 1 g after a meal.[3][5][6][7]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Who should be careful
- People on daily medicines
- Charcoal reduced absorption of every drug tested in the cited studies, including when given hours after the drug.[10][11]
- Suspected poisoning
- Clinical toxicology societies advise against giving charcoal routinely after a poisoning, say it is contraindicated unless the airway is intact or protected, and note that its effect falls quickly after the first hour. Supplement capsules are not a substitute for poison-control or emergency care.[12]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Label dose vs studied doseThe EU-authorised flatulence claim requires 1 g per portion, taken at least 30 minutes before and 1 g shortly after the meal; a lower daily intake (2.08 g split over the day) showed no effect on fecal gases.[3][5]
- Timing with medicinesCharcoal still reduced rivaroxaban exposure by 29% when given 8 hours after the dose, so spacing does not fully remove the interaction.[10]
- Cholesterol doses are very largeCholesterol studies used 16–32 g/day, many times the amount in typical gas products.[6][7]
Cost per studied dose, without the sales pitch
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Cost per studied dose
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Frequently asked questions
Does activated charcoal help with gas and bloating?
Small trials from the 1980s found less gas and bloating than placebo, and the EU allows a flatulence claim at 1 g before and 1 g after a meal. A 1999 study found no effect on fecal gases at 2.08 g/day.[1][2][3][5]
Does activated charcoal interfere with medications?
Yes. It reduced absorption of rivaroxaban, citalopram, ibuprofen and diazepam in healthy volunteers, and still lowered rivaroxaban levels when given 8 hours later.[10][11]
Does activated charcoal detox the body?
It binds substances that are still in the gut, which is why it reduces drug absorption. The studies on this page do not test general detox claims.[10][11]
Does activated charcoal lower cholesterol?
In very small 1980s studies, 16–24 g/day lowered LDL by 29–41%, but a 1988 double-blind trial reported no effect, and these doses are far above typical capsule amounts.[6][7][8]
Does activated charcoal deplete vitamins?
In one 3-week study at 16 g/day, blood levels of vitamins A, E and 25(OH)D did not change.[7]
Sources
- [1]Efficacy of activated charcoal in reducing intestinal gas: a double-blind clinical trial.. Am J Gastroenterol, 1986. RCT
- [2]Effects of orally administered activated charcoal on intestinal gas.. Am J Gastroenterol, 1981. RCT
- [3]Failure of activated charcoal to reduce the release of gases produced by the colonic flora.. Am J Gastroenterol, 1999. open-label
- [4]Scientific Opinion on the substantiation of health claims related to activated charcoal and reduction of excessive intestinal gas accumulation (ID 1938) and reduction of bloating (ID 1938) pursuant to Article 13(1) of Regulation (EC) No 1924/2006.. EFSA J, 2011. review
- [5]Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods (Annex: activated charcoal). European Union (via legislation.gov.uk), 2012. guideline
- [6]Effect of activated charcoal on hypercholesterolaemia.. Lancet, 1986. open-label
- [7]Activated charcoal in the treatment of hypercholesterolaemia: dose-response relationships and comparison with cholestyramine.. Eur J Clin Pharmacol, 1989. crossover-RCT
- [8]No effect of activated charcoal on hyperlipidaemia. A double-blind prospective trial.. Neth J Med, 1988. RCT
- [9]Efficacy of an activated charcoal-simethicone combination in dyspeptic syndrome: results of a randomized prospective study in general practice.. Gastroenterol Clin Biol, 2009. RCT
- [10]Effect of Activated Charcoal on Rivaroxaban Complex Absorption.. Clin Pharmacokinet, 2017. PK-study
- [11]Effect of activated charcoal alone or given after gastric lavage in reducing the absorption of diazepam, ibuprofen and citalopram.. Br J Clin Pharmacol, 1999. PK-study
- [12]Position paper: Single-dose activated charcoal.. Clin Toxicol (Phila), 2005. guideline
What changed
- Independent review: suspected-poisoning entry now cites the AACT/EAPCCT single-dose activated charcoal position paper (PMID 15822758): not routine, contraindicated without an intact or protected airway, effect falls after the first hour. All PMIDs re-checked.
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows. EFSA opinion (PMID 42078776) has no PubMed abstract; the authorised claim wording and conditions of use were read in the annex of Regulation (EU) No 432/2012. Hoekstra 1988 has no abstract and is cited by its title only. Page set indexable.