Filé powder (ground sassafras leaf): Flavor, Cooking Use and Health Facts
Filé powder is earthy and slightly herbal and is stirred into gumbo at the end to thicken it; sassafras root and oil carry a safrole warning, and the one lab test we found found little or none in the leaves.
Content last updated . This page has not been medically reviewed.
In the kitchen at a glance
Flavor:EarthyWarm / woody
Aroma: Earthy and herbal, with a faint spicy note.
Used in: soups and stews
Usual amount in food: No USDA entry and no source we opened gives a usual amount; cooks add it sparingly after the pot is off the heat.
What it is
Filé powder, also called gumbo filé, is dried and ground leaves of the sassafras tree, Sassafras albidum. [1] The tree is native to eastern North America and belongs to the laurel family. [3] The Choctaw people are said to have been the first to use the ground leaves as a seasoning. [1] The French word filé is linked to filer, a verb that can mean "to become ropy", which describes the stringy feel the powder gives when overheated. [1]Flavor and aroma
Filé tastes earthy and a little herbal, and it adds body more than strong flavor. [1] The sources we opened do not describe its smell or name the compounds behind it, so we do not say more. The same sources describe the whole sassafras plant as aromatic and spicy. [3]How it is used in cooking
Filé is used mainly in Louisiana Creole gumbo. [1][2] Gumbo gets its body from okra, filé or roux. Traditionally okra and filé are not used in the same pot, though the rule is sometimes broken. [2]- When to add it: after the vegetables and meat or seafood are cooked and the pot is off the heat. Added during boiling, it makes the gumbo ropey. Many Cajun cooks add it at the table. [2][1]
- Other uses: one source says it can also season soup, gravy and meat. [3]
- Okra out of season: filé can thicken gumbo when okra is not available. [1]
The sources we opened do not name a substitute or say whether to toast it, so we give no rule here.
Normal food amounts
| Measure | Grams | Source |
|---|---|---|
| 1 teaspoon | No USDA entry | USDA SR Legacy has no entry for this spice |
| 1 tablespoon | No USDA entry | USDA SR Legacy has no entry for this spice |
| Typical recipe amount | Not found | We opened no source that states one |
Because USDA SR Legacy has no entry, we give no nutrient numbers. A sprinkle on a bowl of gumbo is a seasoning, not a source of nutrients.
Buying, storing and preparing
- Forms: a fine, dried, green-brown powder of ground leaves. [1] The same plant also gives root bark and oil, which are different products with very different safety rules. [3][4]
- Label check: a seller's claim of "safrole-free" is not something we could check. One FDA study found most leaf samples below the detection limit, while root bark powder, oils, tea concentrate and tinctures were tested too and varied widely. [6]
- Shelf life and storage: the sources we opened give none. A cool, dry, closed jar is a sensible default for any ground herb.
- Do not reheat: the sources we read say heat makes the thickening turn stringy, so add it to the serving, not the pot. [2][1]
Health: what research says
Eating a sprinkle of filé in a bowl of gumbo is very different from drinking sassafras root tea or taking extracts.Food amounts vs supplements
| In normal cooking | In supplements and extracts | |
|---|---|---|
| Typical amount | No official or USDA amount found | Root bark tea and tinctures; a 1997 FDA test found 0.09 to 4.66 mg safrole per cup of brewed root bark tea [6] |
| What studies mostly used | We found no study of filé eaten as food | Safrole was fed to rats and mice at high doses [7] |
| What we can say about benefit | We found no study of any benefit | Sassafras should not be used to treat medical conditions, says MSK [5] |
| Main safety limit | The one leaf test found most samples below detection [6] | Safrole: U.S. rules treat added safrole and oil of sassafras as adulterating food [4] |
What the evidence shows
| Use | What the sources found | Strength of evidence | Form and population |
|---|---|---|---|
| Any health benefit of filé | No study found | Insufficient evidence | Food amounts |
| Safrole and liver cancer | Safrole caused liver cancer in lab animals; MSK says it is reasonably anticipated to be a human carcinogen, and it does not describe liver effects in people. [5] Wikipedia lists a weak liver-cancer effect in rats and mice at higher doses. [7] | Lab or animal only | Rats and mice, high doses |
| Safrole in leaves | In 26 sassafras products, safrole was below the detection limit in most leaf samples, and up to 92.4% in one oil. [6] | Promising but limited | Lab measurement, not a health trial |
| Interference with liver enzymes | In lab tests safrole blocked the enzymes CYP1A2, CYP2A6 and CYP2E1; the effect in people is not described. [5] | Lab or animal only | Laboratory tests |
Official statements
- FDA (US), 21 CFR 189.180: food with added safrole or oil of sassafras is treated as adulterated, including sassafras tea. The section does not mention sassafras leaves or filé. [4]
- MSK Cancer Center: lists safrole as reasonably anticipated to be a human carcinogen; the page does not mention leaves or filé. [5]
- EFSA, EMA, WHO/JECFA: we did not open any statement on filé.
Related pages
Health connections for Filé powder (ground sassafras leaf)
What research links to this spice, and how strong the evidence is. Most studies use concentrated extracts or doses far above what you eat; each card says which.
Safrole level in filé leaf powder
Not enough evidenceIn a 1997 FDA laboratory study of 26 sassafras products, safrole was below the detection limit in most leaf samples.
Supplements: Not a health trial; small number of products; batches may vary.
Lab blocking of liver enzymes by safrole
Lab or animal research onlyIn lab tests safrole inhibited the liver enzymes CYP1A2, CYP2A6 and CYP2E1; MSK does not describe an effect in people.
Supplements: Laboratory finding only; no data for filé.
Pregnancy and breastfeeding
Not enough evidenceMSK gives no pregnancy guidance and we found no source on filé in pregnancy or breastfeeding.
Supplements: No data found.
Any health benefit of filé
Not enough evidenceWe found no study of filé powder for any health use; MSK says sassafras should not be used to treat medical conditions.
Supplements: No study found for food amounts or supplements.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Body systems (1)
- Hepatic / Liver SystemDocumented risk
Safrole from sassafras root and oil caused liver cancer in lab animals; the concern is not shown for filé eaten as food, and one 1997 FDA test found safrole below detection in most leaf samples.
Body parts (1)
- LiverDocumented risk
Safrole from sassafras root and oil caused liver cancer in lab animals; the concern is not shown for filé eaten as food, and one 1997 FDA test found safrole below detection in most leaf samples.
Documented risks and interactions (3)
- Safrole and liver cancer in animals. Safrole, found mostly in sassafras root bark and oil, caused liver cancer in lab animals; MSK lists it as reasonably anticipated to be a human carcinogen.
- US food rule on added safrole and oil of sassafras. Food with added safrole or oil of sassafras is treated as adulterated, including sassafras tea.
- Higher safrole in root bark tea and tinctures. Brewed root bark teas held 0.09 to 4.66 mg of safrole per cup in the 1997 FDA test; one oil reached 92.4%.
Frequently asked questions
Is filé powder sweet?
No. The sources we opened describe it as earthy and used mainly to thicken. [1]
How much is normal?
We found no source that sets an amount; cooks use a small sprinkle off the heat. [1][2]
Is it safe in pregnancy?
The sources we read give no pregnancy guidance for filé. [5] Ask your midwife or doctor.
Can I take it with medicines?
We found no source on filé and medicines. Lab tests show safrole blocking liver enzymes, but the effect in people is not described. [5]
Does filé contain safrole?
In a 1997 FDA study, most leaf samples had safrole below detection, while root products had much more. [6] Only 26 products were tested.
Why not cook it in the pot?
Added during boiling it makes gumbo ropey. [2]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety note at a glance
Safety in more detail
- Medicines: the sources we read do not describe filé and medicines. MSK notes the lab enzyme findings but does not describe a clinical effect. [5] Ask a pharmacist if you take liver-processed medicines.
- Pregnancy: MSK gives no pregnancy guidance. [5] The sources we read do not describe filé in pregnancy.
- Breastfeeding: the sources we read do not describe this.
- Children: the sources we read do not describe this.
- Allergy: the sources we read do not describe allergy to sassafras leaf.
- Liver and kidney: the safrole concern is liver cancer in animals. [5][7] The sources we read do not describe kidney problems.
- Surgery: the sources we read do not describe a surgery warning.
- Quality and contamination: the 1997 study found safrole in leaves below detection in most samples, so batches may vary. [6] We did not find a source on lead or other contamination in filé.
- Amounts that cause trouble: the sources we read give no amount for filé. For root products, MSK says risk rises with the amount and how long it is used. [5]
References
- Wikipedia — Filé powder. https://en.wikipedia.org/wiki/Fil%C3%A9_powder (accessed 2026-10-24)
- Wikipedia — Gumbo. https://en.wikipedia.org/wiki/Gumbo (accessed 2026-10-24)
- Wikipedia — Sassafras albidum. https://en.wikipedia.org/wiki/Sassafras_albidum (accessed 2026-10-24)
- U.S. eCFR — 21 CFR 189.180, Safrole. https://www.ecfr.gov/current/title-21/part-189/section-189.180 (accessed 2026-10-24)
- Memorial Sloan Kettering Cancer Center — Sassafras. https://www.mskcc.org/cancer-care/integrative-medicine/herbs/sassafras (accessed 2026-10-24)
- Carlson MG, Thompson RD — Liquid chromatographic determination of safrole in sassafras-derived herbal products. J AOAC Int 1997; abstract read via Europe PMC. https://pubmed.ncbi.nlm.nih.gov/9325580/ (accessed 2026-10-24)
- Wikipedia — Safrole. https://en.wikipedia.org/wiki/Safrole (accessed 2026-10-24)