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Citrullus colocynthis

Citrullus colocynthis, also known as bitter cucumber, is a fruit-bearing plant. Low doses of its seeds and fruit can reduce blood glucose levels. Higher doses are associated with side-effects like colonic inflammation and rectal bleeding.

Our evidence-based analysis on citrullus colocynthis features 27 unique references to scientific papers.

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Summary of Citrullus colocynthis

Primary information, health benefits, side effects, usage, and other important details

Citrullus colocynthis, also known as bitter cucumber, is a fruit-bearing plant sometimes used medicinally.

Citrullus colocynthis is used to treat diabetes, since it may be able to induce insulin secretion from the pancreas after supplementation, while reducing blood glucose and improving lipid levels.

Preliminary evidence suggests a topical application of Citrullus colocynthis may stimulate hair growth, with an effect comparable to finasteride, a male pattern baldness drug. More evidence is needed to confirm this effect.

Even low doses (100mg, taken three times) of Citrullus colocynthis can cause diarrhea, while higher doses (1,500 mg) can cause colonic inflammation and rectal bleeding. These side-effects stop once supplementation is ceased.

Since the bioactive compounds in Citrullus colocynthis are still unknown, and even low-dose supplementation is associated with intestinal side-effects, Citrullus colocynthis is not recommended for oral supplementation.

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How to Take

Recommended dosage, active amounts, other details

Limited human evidence suggests that 100mg of the seed or dry pulp extract, taken three times a day for a total daily dose of 300mg, is associated with reducing blood glucose and improving lipid levels.

The traditional ‘recommended’ dose for Citrullus colocynthis is 300-800mg. This dosage range is associated with severe intestinal inflammation.

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Human Effect Matrix

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The Human Effect Matrix summarizes human studies to tell you what effects Citrullus colocynthis has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-c Minor - See study
May decrease blood glucose in diabetics at low doses, but the evidence at this moment in time is limited (due to differences between groups at the start of the study)
grade-c Minor - See study
May be able to mildly decrease HbA1c, although the research supporting this claim is very preliminary at this time.
grade-c Minor Moderate See 2 studies
There may be a reduction in total cholesterol in those with high cholesterol, but it has a large degree of variability.
grade-c Minor Moderate See 2 studies
The decrease seen in triglycerides in one study was statistically significance, but the average reduction in hyperlipidemics (16%) has a very large range
grade-c - - See study
No significant influence on blood pressure with up to 300mg of the fruit extract daily over two months
grade-c - - See study
No significant influence on creatinine concentrations with the lowest active dose of the supplement (300mg)
grade-c - Moderate See 2 studies
A possible benefit in hyperlipidemics only has failed to reach statistical significance.
grade-c - Moderate See 2 studies
A possible reduction seen in persons with high blood triglycerides and cholesterol failed to reach statistical significance due to large variance.
grade-c - Very High See 2 studies
Both studies using 300mg of either the fruit or seed extract have failed to find alterations in liver enzymes associated with supplementation.
grade-c - - See study
No significant alterations in serum urea, suggesting no renal toxicity with the low doses (300mg) of this supplement
grade-c - - See study
In assessing the influence of the fruit extract on blood glucose, there was no significant influence on weight

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Things to Note

Primary Function:

Also Known As

Bitter apple, desert gourd, bitter cucumber

Do Not Confuse With

Bitter Gourd/Melon/Squash (Momordica charantia)

Caution Notice

Known toxicity associated with rectal bleeding

  • While the toxicity is reversible within two weeks, consumption of over a gram of the fruits or seeds (dry weight basis) results in intestinal inflammation and rectal bleeding; it is not known if long term damage occurs from this

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Click here to see all 27 references.