Evidence-based·Last reviewed June 1, 2026·How we grade evidence

cucumber

Botanical

A hydrating, low-calorie food — 95% water, modest source of vitamin K and potassium. Cucumber-extract supplements marketed for joint comfort have one small industry-funded RCT showing comparable effect to glucosamine/chondroitin; independent replication is limited. As a food, cucumber is excellent for hydration, low-FODMAP IBS diets, and dietary potassium.

Quick decision guide

May help most

A hydrating, low-calorie addition to meals; people following low-FODMAP or low-calorie diets; a modest source of vitamin K and potassium.

Common dosing range

Food: 100–300 g (half to a whole medium cucumber) is a typical serving. Supplement extract: in the published trial, 10 mg twice daily of standardized Cucumis sativus extract (Q-Actin / iQ-9).

When to expect effects

Immediate for hydration; weeks-to-months for supplement-extract use on joint symptoms in the single RCT.

Watch out for

Conventional cucumbers are sometimes waxed — peel or wash thoroughly. Cucumber-extract joint supplements have weak evidence; established choices (NSAIDs, acetaminophen, physical therapy, weight management) work better for symptomatic knee osteoarthritis.

Evidence snapshot

Hydration and dietary fluidStrong
Low-calorie satiety foodModerate
Vitamin K and potassium sourceModerate
Knee joint pain (extract supplement)Low

What is it

Cucumber (Cucumis sativus) is a watery fruit of the gourd family, used in supplements as fresh powder, juice, or freeze-dried whole-food ingredient and as cucumber seed extract.

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You want a high-water, low-calorie vegetable that's easy to add to salads, sandwiches, and snacks
You're following a low-FODMAP diet for IBS — cucumber is well tolerated at standard serving sizes
You want a hydrating side that contributes modest vitamin K and potassium without much sodium or sugar
You're tracking calories and looking for filling, nutrient-dense low-calorie options

Probably skip if…

You're hoping cucumber-extract capsules will reliably treat knee osteoarthritis — evidence is one industry-funded RCT; standard care works better
You're using 'cucumber detox water' as a meaningful detox protocol — your liver and kidneys do the detoxing; the cucumber is just flavoring
You're avoiding vitamin K because you're on warfarin and aiming for tight INR control — keep cucumber intake consistent, not avoided, to stabilize INR
You're hoping topical cucumber slices will reverse skin aging — there's no controlled evidence beyond temporary cooling and contact moisturization

Evidence at a glance

Hydration and dietary fluid contribution

Strong Evidence
Effect
300 g cucumber ≈ 285 g water — about 10% of an average adult's daily fluid target from a single serving
Best fit
People in hot climates, active individuals, anyone struggling to drink enough plain water, and those on diets emphasizing satiety per calorie
Time
Immediate (gastric emptying within 30–60 minutes)

Vitamin K and potassium intake

Good Evidence
Effect
100 g cucumber provides ~14% DV vitamin K and ~3% DV potassium
Best fit
Anyone looking to boost vegetable variety with low-calorie options that contribute vitamin K
Time
N/A — nutrient content

Low-FODMAP / IBS-friendly food

Good Evidence
Effect
Rated low FODMAP at typical serving sizes; tolerated by most IBS patients on elimination phase
Best fit
Adults with IBS following a low-FODMAP diet under dietitian guidance
Time
Per-meal tolerance

Knee osteoarthritis (cucumber extract)

Limited Evidence
Effect
Comparable WOMAC pain and function reduction to glucosamine + chondroitin over 180 days; no placebo control
Best fit
Adults curious about a non-NSAID, non-glucosamine joint-comfort option; reasonable if standard therapies haven't been tolerated
Time
Weeks to months in the 180-day trial

Evidence for 4 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Hydration and dietary fluid contribution

Supplement benefit
Strong Evidence

Cucumber is ~95% water by weight (USDA FoodData Central), making it one of the most water-dense common foods. The 2010 Popkin review estimates that water-rich foods contribute roughly 20–25% of total daily fluid intake in typical Western diets. A 300 g cucumber (one medium) provides about 285 g of water — meaningful when daily fluid recommendations are 2.7 L (women) to 3.7 L (men) from all sources. Cucumber's low energy density (15 kcal/100 g) means it can replace higher-calorie snacks without compromising hunger or satiety.

Effect size
300 g cucumber ≈ 285 g water — about 10% of an average adult's daily fluid target from a single serving
Time to effect
Immediate (gastric emptying within 30–60 minutes)
Best fit
People in hot climates, active individuals, anyone struggling to drink enough plain water, and those on diets emphasizing satiety per calorie
Less likely
Healthy people with no hydration issues — water itself is just as effective

Bottom line: A practical way to add fluid and crunchy texture to meals with virtually no calories. Don't rely on it as your only hydration source.

SourceUSDA FoodData Central — Cucumber, with peel, raw — USDAPopkin et al., 2010 — Water, hydration, and health — PubMed — Nutr Rev

Vitamin K and potassium intake

Supplement benefit
Good Evidence

Cucumber with peel provides 16 µg vitamin K per 100 g (~14% DV) and 147 mg potassium (~3% DV), per USDA FoodData Central. Cucumber's main contribution is vitamin K — useful for blood-clotting function and bone mineralization. The vitamin K is concentrated in the peel, so peeled cucumber gives less. Potassium content is modest; bananas (358 mg/100 g), avocado (485 mg/100 g), or sweet potato (337 mg/100 g) are denser sources.

Effect size
100 g cucumber provides ~14% DV vitamin K and ~3% DV potassium
Time to effect
N/A — nutrient content
Best fit
Anyone looking to boost vegetable variety with low-calorie options that contribute vitamin K
Less likely
People needing concentrated potassium (e.g., for hypokalemia or active diuretic therapy) — pick denser sources

Bottom line: Useful background contribution to vitamin K intake; don't count on cucumber for substantial potassium.

SourceUSDA FoodData Central — Cucumber, with peel, raw — USDA

Low-FODMAP / IBS-friendly food

Supplement benefit
Good Evidence

Monash University's FODMAP testing rates cucumber as low FODMAP at standard serving sizes (75–150 g), making it well-tolerated by people on a low-FODMAP diet for irritable bowel syndrome. Cucumber's low fermentable carbohydrate content and high water content make it a safe choice when many other vegetables are restricted. Combined with its low calorie density and culinary versatility, it's a practical staple for IBS-friendly meals.

Effect size
Rated low FODMAP at typical serving sizes; tolerated by most IBS patients on elimination phase
Time to effect
Per-meal tolerance
Best fit
Adults with IBS following a low-FODMAP diet under dietitian guidance
Less likely
People with specific cucurbit allergy or symptomatic gastroparesis

Bottom line: A reliable low-FODMAP vegetable that adds crunch and water to meals without triggering most IBS symptoms.

SourceMonash University FODMAP App — Cucumber — Monash University

Knee osteoarthritis (cucumber extract)

Supplement benefit
Limited Evidence

Nash et al. 2018 (PMID 30538478) randomized 122 adults with mild-to-moderate knee osteoarthritis to standardized Cucumis sativus extract (Q-Actin, 10 mg twice daily) or glucosamine + chondroitin (1,350 mg + 1,125 mg) for 180 days. WOMAC pain and function scores improved in both groups, with cucumber extract showing comparable effects. The trial had no placebo arm and was funded by the cucumber-extract manufacturer. Independent replication has not been published. Mechanism is attributed to cucurbitacins and iminosugars in the extract with potential anti-inflammatory activity.

Effect size
Comparable WOMAC pain and function reduction to glucosamine + chondroitin over 180 days; no placebo control
Time to effect
Weeks to months in the 180-day trial
Best fit
Adults curious about a non-NSAID, non-glucosamine joint-comfort option; reasonable if standard therapies haven't been tolerated
Less likely
Severe knee osteoarthritis requiring surgical evaluation; anyone expecting a strong analgesic effect — modest improvement is the realistic ceiling

Bottom line: One small industry-funded trial. Reasonable to try if you've exhausted standard options, but don't pay a premium expecting strong effect.

Evidence is mixed

Single industry-funded trial with no placebo arm. Comparable to glucosamine/chondroitin doesn't establish superiority over placebo since glucosamine/chondroitin's own placebo-controlled evidence is mixed (GAIT trial). Independent replication needed.

SourceNash et al., 2018 — Cucumber extract for knee osteoarthritis RCT — PubMed — Clin Interv Aging· conflicting
SourceNash et al., 2018 — Cucumber extract for knee osteoarthritis RCT — PubMed — Clin Interv Aging

How it works

Cucumber is roughly 95% water with trace amounts of vitamin K, vitamin C, and silica. Standardized cucumber extracts (such as Q-Actin) have been studied for joint comfort, possibly via silicon, glycosaminoglycans, or unidentified polyphenols. Freeze-dried cucumber powder concentrates these constituents and is used in green-food blends and joint formulas.

How to take it

1. Typical dose
• Food: ½ to 1 medium cucumber (100–300 g) per serving as a salad, snack, or sandwich vegetable • Low-FODMAP serving: up to 150 g per meal is well-tolerated • Supplement extract: 10 mg twice daily of standardized Cucumis sativus extract was used in the Nash 2018 joint trial
2. Higher studied dose
Up to 30 mg/day cucumber-extract has been used in pilot work without notable adverse events. Whole-food consumption is essentially open-ended at culinary serving sizes.
3. Timing
Eat any time — particularly useful as a hydrating snack between meals, a side at lunch or dinner, or sliced into water for flavor. Wash thoroughly before eating; peel if cucumber is waxed or conventionally grown and you're concerned about pesticide residue.
4. With food
Either as a food itself or alongside other meals.
5. Split dosing
N/A for the food. Extract supplement is dosed twice daily in the published trial.
6. How long to try
Indefinite as a food. For the supplement extract joint use, 180 days in the published trial; reassess after 3 months whether you notice symptom improvement.

What to track

Joint pain and stiffness (WOMAC or simple 1–10 scale) if trialing the extract for OA
Daily vegetable variety and total fluid intake
IBS symptoms if using as a low-FODMAP staple
Vitamin K intake stability if on warfarin (don't avoid cucumber — keep intake consistent)

Bottom line: Eat cucumber as a routine vegetable for hydration and vitamin K — that's the strongest case. Cucumber-extract supplements for joints are a weak bet with one industry-funded trial.

6 commercial forms

Compare the main delivery options and what they’re best suited for.

Fresh whole cucumber (with peel)

Most nutrient-dense

Standard slicing or English cucumber, eaten with peel for maximum vitamin K. Wash thoroughly; peel if conventionally grown and waxed. The 'default' culinary form.

Peel concentrates vitamin K and most antioxidant content.

Persian or English cucumbers

Thinner skin

Smaller, seedless varieties with thinner skin and milder flavor. Less vitamin K per 100 g than thick-skinned slicers (less peel by weight), but easier to eat whole without peeling.

Easier to eat skin-on; modest nutrient trade-off.

Pickled cucumber (pickles)

High sodium

Fermented or vinegar-brined cucumber. Adds substantial sodium (often 250–700 mg per pickle) and reduces fresh-water content. Pickling can preserve some vitamins; fermented versions add probiotic bacteria.

Sodium-heavy; nutrient profile shifts away from fresh.

Cucumber juice or smoothie ingredient

Liquid form

Juicing concentrates water and loses fiber; blending preserves fiber. Useful for adding mild flavor and hydration to green smoothies. Drink fresh — cucumber juice oxidizes quickly.

Fiber loss with juicing; preserved with blending.

Standardized cucumber extract supplement (Q-Actin, iQ-9)

Joint-comfort product

Concentrated extract standardized for cucurbitacins and iminosugars, sold for knee joint comfort. Single industry-funded RCT; independent evidence is limited.

Concentrated; limited independent evidence.

Cucumber seed oil (cosmetic)

Topical use

Cold-pressed seed oil used as a moisturizer or hair treatment. Light texture, mild scent. Topical cosmetic use only; no internal-use evidence.

Topical use, not for ingestion.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

no notable side effects from food intakeoccasional belching or mild bloating from raw cucumber's water and fiber content

Serious risks

Who should avoid it

Pregnancy & breastfeeding

Cucumber is a safe and commonly consumed pregnancy food. Wash thoroughly to reduce foodborne-pathogen risk (listeria, salmonella). Cucumber-extract supplements have not been studied in pregnancy and should be avoided in favor of food-form intake.

SourceUSDA FoodData Central — Cucumber, with peel, raw — USDA

Bottom line: Cucumber is a safe routine food for almost everyone. Wash before eating; skip the extract supplements during pregnancy.

Interactions

warfarin and other vitamin K antagonist anticoagulantsMinor

Cucumber with peel provides ~14% DV vitamin K per 100 g — relevant only with very large or inconsistent intake. Keep cucumber intake consistent (don't drastically increase or eliminate) if on warfarin and monitoring INR.

SourceUSDA FoodData Central — Cucumber, with peel, raw — USDA
diabetes medications (extract form only)Minor

Theoretical additive hypoglycemic effect from concentrated cucumber-seed or whole-fruit extracts; clinically meaningful interaction from culinary cucumber is unlikely.

SourceMukherjee et al., 2013 — Phytochemistry and pharmacology of Cucumis sativus — PubMed — Fitoterapia

Food sources

Cucumber, with peel, raw

Amount
100 g (vitamin K 16.4 µg)
%DV
14%

Cucumber, with peel, raw

Amount
1 medium / 300 g (vitamin K 49 µg)
%DV
41%

Cucumber, with peel, raw

Amount
100 g (potassium 147 mg)
%DV
3%

Cucumber, with peel, raw

Amount
1 medium / 300 g (potassium 442 mg)
%DV
9%

Cucumber, with peel, raw

Amount
100 g (vitamin C 2.8 mg)
%DV
3%

Cucumber, with peel, raw

Amount
100 g (water 95.2 g)
%DV
—

Cucumber, peeled, raw

Amount
100 g (vitamin K 7.2 µg)
%DV
6%

Pickles, cucumber, dill

Amount
1 pickle / 65 g (sodium 569 mg)
%DV
25%

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

Fresh cucumbers: firm, brightly colored, free of soft spots or yellowing
Choose organic if peel will be eaten — conventional cucumbers are often waxed and may carry pesticide residues
English (seedless) cucumbers and Persian cucumbers have thinner skins and milder flavor; standard slicers have thicker peel with more vitamin K
Refrigerate at 50–55 °F (10–13 °C) in a high-humidity drawer; eat within a week
Supplement extract: look for Cucumis sativus with standardized extract ratio (e.g., 'Q-Actin') and a manufacturer with third-party verification

Be skeptical of…

'Cucumber detox water' marketed as a meaningful detox protocol — flavoring water does not enhance detoxification
Anti-aging or skin-rejuvenation claims for topical cucumber slices — beyond temporary cooling and contact moisturization, no controlled evidence
Mega-dose cucumber extract for general 'inflammation' — only joint use has any RCT data, and even that is limited
Weight-loss claims beyond cucumber's low calorie content — there's nothing special metabolically; the calorie reduction is the mechanism
'Hydration superfood' marketing at premium prices — cucumber is cheap; spending more doesn't add hydration

Frequently asked questions

Is cucumber a good source of nutrients?⌄

It's mostly water with small amounts of vitamins and minerals. Useful for hydration; concentrated extracts target specific joint claims.

References by claim

Hydration and dietary fluid contribution

USDA FoodData Central — Cucumber, with peel, raw — USDA (2024) link

Popkin et al., 2010 — Water, hydration, and health — PubMed — Nutr Rev (2010) link

Knee osteoarthritis (cucumber extract)

Nash et al., 2018 — Cucumber extract for knee osteoarthritis RCT — PubMed — Clin Interv Aging (2018) link

Safety

Mukherjee et al., 2013 — Phytochemistry and pharmacology of Cucumis sativus — PubMed — Fitoterapia (2013) link

Low-FODMAP / IBS-friendly food

Monash University FODMAP App — Cucumber — Monash University (2024) link

Other references

Cucumber (Cucumis sativus) on Wikidata — Wikidata link

Track cucumber with Pilora

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Evidence-based·Last reviewed Jun 1, 2026·Evidence current as of Jun 1, 2026·How we grade evidence

Disclaimer: 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.