Wheatgrass
A young wheat-plant juice or powder marketed as a 'superfood' detoxifier. The popular health claims (chlorophyll → blood, detoxification, cancer prevention) aren't supported by human evidence. The one solid trial is a small 2002 RCT showing it modestly helped active ulcerative colitis. Otherwise, treat it like a green-juice ingredient with negligible nutritional density per dose.
Quick decision guide
May help most
Curious users who want to try a complementary option for mild active ulcerative colitis alongside their gastroenterologist's regimen — or anyone who simply enjoys green juice.
Common dosing range
100 mL fresh juice or 1–4 g powder per day (1–2 oz fresh juice = approx. 1 shot).
When to expect effects
Weeks — Ben-Arye trial measured effects at 1 month.
Watch out for
Common nausea / GI upset, especially when starting. People with grass/wheat allergies should avoid. 'Detox' marketing is not evidence-based — don't substitute for prescribed treatment.
Evidence snapshot
What is it
Wheatgrass is the young grass of the common wheat plant (Triticum aestivum), harvested before the grain forms. It is consumed fresh-juiced or as a powder and is marketed for its chlorophyll, vitamin, and mineral content.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
Active distal ulcerative colitis (adjunct) Limited Evidence | ≈1 point reduction on a 4-fold disease activity index over placebo; reduction in rectal bleeding score (Ben-Arye 2002, n=23) | Adults with mild-to-moderate active distal UC already on standard therapy who want to try an adjunct under medical supervision | ≈1 month in the trial |
Cancer prevention or treatment Mixed Evidence | No human cancer outcome data | None — supportive use during chemotherapy was reported in one small trial but is not generalizable | Not established for human cancer endpoints |
General antioxidant / wellness Mixed Evidence | No clinical-endpoint benefit in healthy adults | People who genuinely enjoy the taste and use it as part of a varied diet | Not established for general-wellness endpoints |
Detoxification / body cleansing Weak Evidence | No measured human benefit on any validated detoxification marker | No clinical population shown to benefit | Not established |
Active distal ulcerative colitis (adjunct)
- Effect
- ≈1 point reduction on a 4-fold disease activity index over placebo; reduction in rectal bleeding score (Ben-Arye 2002, n=23)
- Best fit
- Adults with mild-to-moderate active distal UC already on standard therapy who want to try an adjunct under medical supervision
- Time
- ≈1 month in the trial
Cancer prevention or treatment
- Effect
- No human cancer outcome data
- Best fit
- None — supportive use during chemotherapy was reported in one small trial but is not generalizable
- Time
- Not established for human cancer endpoints
General antioxidant / wellness
- Effect
- No clinical-endpoint benefit in healthy adults
- Best fit
- People who genuinely enjoy the taste and use it as part of a varied diet
- Time
- Not established for general-wellness endpoints
Detoxification / body cleansing
- Effect
- No measured human benefit on any validated detoxification marker
- Best fit
- No clinical population shown to benefit
- Time
- Not established
Evidence for 4 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
Active distal ulcerative colitis (adjunct)
Disease adjunctThe strongest single piece of evidence is Ben-Arye 2002, a 23-patient placebo-controlled RCT in which 100 mL/day wheat grass juice for 1 month reduced disease activity index (p=0.031) and rectal bleeding severity (p=0.025) vs placebo, with no serious adverse events. The trial is small, single-center, and has never been formally replicated. Use only as adjunct — not in place of 5-ASA or biologic therapy.
Bottom line: Single small RCT supports modest symptomatic benefit as an adjunct. Don't expect drug-level effect, don't replace standard care, and tell your GI doctor before starting.
Cancer prevention or treatment
Mechanism onlyWheatgrass contains chlorophyll, flavonoids, and small amounts of vitamins A, C, and E. Cell-culture and animal studies show antioxidant and antiproliferative effects, but those have not translated into human cancer-prevention or treatment trials. MSKCC's About Herbs monograph explicitly states wheatgrass cannot be recommended for cancer treatment or prevention.
Bottom line: Preclinical signal, no clinical proof. Don't pay premium prices for cancer-prevention marketing.
General antioxidant / wellness
Mechanism onlyWheatgrass juice contains chlorophyll and antioxidant pigments. Per-dose nutritional density is similar to other dark leafy greens but smaller in volume — a 1-oz shot is not a meaningful source of any vitamin or mineral. The case for it over simply eating more vegetables is largely marketing.
Bottom line: A bitter green shot isn't more medicinal than spinach or kale. Skip it if you don't enjoy it.
Detoxification / body cleansing
Mechanism onlyThe 'detox' claim is the most-marketed and least-supported use. NCCIH's review of detox products notes there is no convincing evidence that they remove toxins or improve health, and that the liver, kidneys, lungs, and skin handle endogenous detoxification continuously without supplemental help. No clinical trial has shown wheatgrass alters any measured toxin biomarker in humans.
Bottom line: Treat 'detox' as marketing language. If you enjoy the juice, drink it — but it isn't doing anything special to your liver or kidneys.
How it works
How to take it
What to track
Bottom line: Start with 1 oz fresh juice or 1 g powder, ideally with food. Try for 1 month if using as a UC adjunct. Stop if you get persistent nausea or any allergic symptoms.
4 commercial forms
Compare the main delivery options and what they’re best suited for.
Fresh wheatgrass juice
Used in the RCTCold-pressed from 7-10 day old wheatgrass blades. Highly perishable — must be consumed within minutes for full nutrient content, or refrigerated and used within 24-48 hours. This is the form the Ben-Arye UC trial used.
Most studied form for the modest evidence that exists.
Wheatgrass powder
Shelf-stableFreeze-dried or spray-dried whole wheatgrass. Convenient but generally lower in heat-sensitive compounds than fresh juice. Reconstitute in water or smoothies; typical dose 1-4 g/day.
Less direct trial data than fresh juice; convenience trade-off.
Wheatgrass tablets
Lowest potencyCompressed powder. Provides only small per-tablet amounts; you'd need many tablets to match a juice dose. Often the least cost-effective form per gram.
Same powder limitations, even more diluted per serving.
Frozen wheatgrass juice shots
ConvenientPre-juiced and flash-frozen in single-serve cups. A compromise between freshness and convenience. Thaw in the fridge and drink immediately.
Likely close to fresh-juice potency if cold-chain is intact.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Bacterial contamination of fresh juice — wheatgrass is grown in damp trays and consumed raw. Mold or bacterial growth has caused GI infection. Use reputable suppliers and refrigerate fresh juice.
Allergic reactions — including throat tightness, hives, and (rarely) anaphylaxis in people with wheat or grass allergy.
Who should avoid it
- Anyone with celiac disease, wheat allergy, or grass pollen allergy — even though young wheatgrass blades are theoretically gluten-free, grain contamination is common and proteins may cross-react.
- Pregnant or breastfeeding women — no safety data; raw juice contamination risk is a concern.
- Immunocompromised individuals (chemotherapy, transplant, severe IBD on biologics) — bacterial contamination risk from fresh juice is more dangerous.
Pregnancy & breastfeeding
No human safety data exist. Avoid fresh wheatgrass juice during pregnancy because of potential bacterial contamination of raw plants. Talk to your obstetrician before using any wheatgrass product during pregnancy or breastfeeding.
Bottom line: Generally well tolerated by healthy adults, but nausea is common. Skip it if pregnant, immunocompromised, or allergic to wheat or grasses.
Interactions
Wheatgrass contains vitamin K (as all green vegetables do). High consumption can theoretically reduce warfarin effect. Keep intake stable rather than alternating high-vs-zero days.
Food sources
| Food | Amount | %DV |
|---|---|---|
| Wheatgrass juice, fresh | 1 oz (30 mL, ~5 kcal) | — |
| Wheatgrass juice — vitamin A (RAE) | 1 oz (~60 mcg) | 7% |
| Wheatgrass juice — vitamin C | 1 oz (~1 mg) | 1% |
| Wheatgrass juice — vitamin K | 1 oz (~20 mcg) | 17% |
| Wheatgrass juice — iron | 1 oz (~0.5 mg) | 3% |
| Wheatgrass juice — chlorophyll (not a vitamin) | 1 oz (~10–20 mg) | — |
Wheatgrass juice, fresh
- Amount
- 1 oz (30 mL, ~5 kcal)
- %DV
- —
Wheatgrass juice — vitamin A (RAE)
- Amount
- 1 oz (~60 mcg)
- %DV
- 7%
Wheatgrass juice — vitamin C
- Amount
- 1 oz (~1 mg)
- %DV
- 1%
Wheatgrass juice — vitamin K
- Amount
- 1 oz (~20 mcg)
- %DV
- 17%
Wheatgrass juice — iron
- Amount
- 1 oz (~0.5 mg)
- %DV
- 3%
Wheatgrass juice — chlorophyll (not a vitamin)
- Amount
- 1 oz (~10–20 mg)
- %DV
- —
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
Is wheatgrass gluten-free?⌄
Pure wheatgrass harvested before grain formation typically does not contain gluten, but cross-contamination during processing is possible. If you have celiac disease or wheat allergy, choose products certified gluten-free.
Why does wheatgrass make some people nauseous?⌄
The high concentration of chlorophyll, fiber, and bitter compounds can irritate the stomach in some people, especially on an empty stomach. Reducing the dose or taking it with food usually resolves nausea.
Is chlorophyll the same as hemoglobin?⌄
Chlorophyll and hemoglobin have structurally similar ring molecules, but with magnesium at the center of chlorophyll versus iron in hemoglobin. The two are different molecules with different functions, and chlorophyll is not converted to hemoglobin in the body.
How much wheatgrass juice should I drink per day?⌄
Common servings are 30 to 60 mL (1 to 2 oz) of fresh juice per day. Start with smaller amounts and increase gradually to assess tolerance.
References by claim
Active distal ulcerative colitis (adjunct)
Cancer prevention or treatment
Bar-Sela et al., 2015 — Mini-Reviews in Medicinal Chemistry (via PubMed) (2015) link
Detoxification / body cleansing
NCCIH — ‘Detoxes’ and ‘Cleanses’: What You Need To Know (2024) link
Other references
Wheatgrass on Wikidata — Wikidata link
Track Wheatgrass with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.