Wild celery extract (celery seed)
Summary
Celery seed extract comes from wild celery (Apium graveolens). A 2025 meta-analysis of 10 trials (511 people) found lower blood pressure, fasting glucose and triglycerides, with seed preparations above 1,000 mg/day working best. The main seed trial used 1.34 g/day for 4 weeks alongside usual blood-pressure drugs. Celery can trigger allergy and sun-sensitive rashes.
Key facts
- Extract of the seed (or leaf) of Apium graveolens; seed extracts contain 3-n-butylphthalide[2]
- 10 RCTs, 511 participants: lower systolic and diastolic blood pressure, fasting glucose and triglycerides; no effect on total, LDL or HDL cholesterol[1]
- 1.34 g/day seed extract for 4 weeks: 24-hour systolic BP fell from 141.2 to 130.0 mmHg and diastolic from 92.2 to 84.2 mmHg; no change on placebo[2]
- Celery is one of the 14 allergens UK (and EU) food law requires to be declared; allergy is confirmed by food challenge and the major allergen is Api g 1[6][9]
- Celery contains furocoumarins and psoralens that can cause blistering rashes on sun-exposed skin; normal dietary amounts are usually too low, but tanning-bed use and heavy exposure raise the risk[7]
- 5 graded human outcomes on this page
- October 13, 2026
How it works
ProposedCelery seed contains phthalides such as 3-n-butylphthalide, flavonoids and furocoumarins. The trial authors attribute the blood-pressure effect to 3-n-butylphthalide; the mechanism in people is not established.[2][3]
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 |
|---|---|---|---|---|
| Blood pressure | Grade C | Improved | Meta-analysis of 10 trials · n = 511 · 2025 | 2 rows |
| Blood sugar | Grade D | Improved | Crossover RCT · n = 51 · 2022 | 2 rows |
| Mood | Grade D | Improved | Crossover RCT · n = 50 · 2023 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Blood pressure, fasting glucose and lipids | Improved | Grade C | Meta-analysis · n = 511 · 2025 Adults in 10 randomised trials Form: Celery seed, leaf or other celery preparations · Dose: Varied (seed preparations above 1,000 mg/day did best) · Duration: Varied Systolic BP (SMD −1.0), diastolic BP (SMD −0.93), fasting glucose (SMD −0.80) and triglycerides (SMD −1.18) fell; total, LDL and HDL cholesterol did not change; adverse events did not differ from placebo. | 40765738 (opens PubMed)Source [1] |
| 24-hour ambulatory blood pressure in hypertension | Improved | Grade D | Crossover RCT · n = 52 · 2022 Adults with hypertension on usual medication (Iran) Form: Celery seed extract capsules · Dose: 1.34 g/day (4 capsules) · Duration: 4 weeks per period Systolic BP fell from 141.2 to 130.0 mmHg and diastolic from 92.2 to 84.2 mmHg with celery, with no significant change on placebo; no excess side effects. | 35624525 (opens PubMed)Source [2] |
| Fasting glucose, lipids, kidney and liver markers | Improved | Grade D | Crossover RCT · n = 51 · 2022 Adults with hypertension on usual medication (Iran) Form: Celery seed extract capsules · Dose: 1.34 g/day · Duration: 4 weeks per period Fasting glucose fell from 108.53 to 97.96 mg/dL; total cholesterol, triglycerides and LDL fell and HDL rose; blood counts and electrolytes did not change. | 35536382 (opens PubMed)Source [3] |
| Anxiety and depression scores in hypertension | Improved | Grade D | Crossover RCT · n = 50 · 2023 Adults with hypertension on usual medication (Iran) Form: Celery seed extract capsules · Dose: 1.34 g/day · Duration: 4 weeks per period Beck Anxiety scores fell by 6.78 points and Beck Depression scores by 3.63 points during celery periods. | 36334223 (opens PubMed)Source [4] |
| Blood glucose in older adults with prediabetes | Improved | Grade D | RCT · n = 16 · 2018 Adults over 60 with prediabetes (Indonesia) Form: Celery leaf extract capsules · Dose: 250 mg three times daily (750 mg/day) · Duration: 12 days Pre- and post-meal glucose fell significantly; insulin did not change significantly. | 29436564 (opens PubMed)Source [5] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Celery seed extract (capsules) | Varies[2] | No human absorption data in the cited sources.[2] | No excess side effects versus placebo over 4 weeks at 1.34 g/day; kidney and liver markers improved slightly.[2][3] | Blood-pressure, metabolic and mood outcomes (1.34 g/day) |
| Celery leaf extract (capsules) | Varies[5] | No human absorption data in the cited sources.[5] | No safety problems reported in the abstract over 12 days.[5] | Prediabetes glucose study (750 mg/day) |
Studied doses
Doses studied in human trials ranged from 750 mg/day of celery leaf extract (12 days) to 1.34 g/day of celery seed extract (4 weeks); a meta-analysis found seed preparations above 1,000 mg/day performed best.[5][2][1]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Blood-pressure medicinesRCTIn trials, 1.34 g/day seed extract added to usual blood-pressure drugs lowered systolic pressure by about 11 mmHg; the combined effect could push pressure too low in some people.[2][3]
- Diabetes medicinesRCTSeed extract lowered fasting glucose by about 10 mg/dL in 4 weeks and leaf extract lowered glucose in prediabetes; effects could add to glucose-lowering drugs.[3][5][1]
- Photosensitising medicinesReviewCelery furocoumarins and psoralens are photosensitising; combining them with other photosensitisers or tanning beds could raise the risk of phototoxic rashes. Not studied with extracts.[7][8]
Who should be careful
- Celery allergy
- Celery is a regulated food allergen (one of 14 that must be declared in the UK and EU) and can cause reactions confirmed by double-blind food challenge; people allergic to celery should avoid celery extracts.[6][9]
- Sun-sensitive skin or tanning-bed users
- Celery furocoumarins can cause phytophotodermatitis on sun-exposed skin, and a phototoxic rash has been reported after a celery diet.[7][8]
- Low blood pressure or on several blood-pressure drugs
- Seed extract lowered blood pressure substantially when added to usual medication.[2]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
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Frequently asked questions
What is wild celery extract?
An extract of the seeds (or sometimes leaves) of Apium graveolens, the plant cultivated as celery.[2]
Does celery seed lower blood pressure?
A meta-analysis of 10 small trials found lower blood pressure, and one 4-week trial reported about 11/8 mmHg falls when added to usual medication.[1][2]
Does it lower blood sugar?
Pooled trials found lower fasting glucose, and seed extract cut fasting glucose by about 10 mg/dL in 4 weeks.[1][3]
Can celery cause rashes?
Yes. Celery contains psoralens that can cause blistering rashes on sun-exposed skin.[7]
Is it safe with blood-pressure medicines?
Effects may add up; the main trial gave it alongside usual drugs and blood pressure fell substantially.[2]
Sources
- [1]Effects of celery (Apium graveolens) on blood pressure, glycemic and lipid profile in adults: a systematic review and meta-analysis of randomized controlled trials.. Front Nutr, 2025. meta-analysis
- [2]Effect of celery (Apium graveolens) seed extract on hypertension: A randomized, triple-blind, placebo-controlled, cross-over, clinical trial.. Phytother Res, 2022. crossover-RCT
- [3]Safety evaluation and biochemical efficacy of celery seed extract (Apium Graveolens) capsules in hypertensive patients: a randomized, triple-blind, placebo-controlled, cross-over, clinical trial.. Inflammopharmacology, 2022. crossover-RCT
- [4]Beneficial effects of celery seed extract (Apium graveolens), as a supplement, on anxiety and depression in hypertensive patients: a randomized clinical trial.. Inflammopharmacology, 2023. crossover-RCT
- [5]The effects of celery leaf (apium graveolens L.) treatment on blood glucose and insulin levels in elderly pre-diabetics.. Saudi Med J, 2018. RCT
- [6]Clinical reactivity of celery cultivars in allergic patients: Role of Api g 1.. Clin Exp Allergy, 2018. observational
- [7]Not as Bland as You May Think: Celery (Apium graveolens) Commonly Induces Phytophotodermatitis.. Cutis, 2025. review
- [8]Image Gallery: Phototoxic rash from celery diet.. Br J Dermatol, 2016. observational
- [9]Allergen guidance for food businesses. Food Standards Agency (UK), 2020. guideline
What changed
- Independent adversarial review: added the regulatory allergen status (celery is one of the 14 declarable allergens in UK/EU law); sun-sensitivity key fact now keeps the source's caveat that dietary amounts are usually too low; Api g 1 allergy study re-typed as observational (diagnostic food-challenge study, not a treatment RCT).
- Second-pass self-review: every PMID re-checked against NCBI esummary (title, year, no retraction or expression-of-concern flag), every dose, n and duration re-read against the PubMed abstract or PMC full text, grades held conservative, and interactions limited to what a cited source supports.
- First draft. Source titles and years taken from NCBI E-utilities esummary; abstracts read for every evidence row.