Diosmin for hemorrhoids: what the trials show

Diosmin is a flavonoid, a plant compound found in citrus peel, and it is the natural remedy for hemorrhoids with the most clinical trials behind it. Most of those trials tested a purified mix of 90 percent diosmin and 10 percent hesperidin, often called MPFF (micronized purified flavonoid fraction). Doctors group these pills with other vein-toning drugs under the name phlebotonics.

The short version: diosmin pills seem to help bleeding during a flare, the help for pain and itching is less certain, and many of the trials were small or poorly run. This page walks through what each major review found, how the pills were used in the trials, who should check before taking them, and how they fit with the rest of the natural remedies for hemorrhoids that have evidence.

How diosmin is supposed to help hemorrhoids

Hemorrhoids are cushions of blood vessels in the anal canal. When they swell, they bleed, itch and ache. Phlebotonics are thought to improve the tone of vein walls, steady how leaky small blood vessels are, and help fluid drain away, although the exact mechanism has not been fully worked out ¹. That is why the same pills are sold for heavy, swollen legs.

The idea is that firmer, less leaky vessels bleed and swell less. The trials test whether people actually notice that, and the answer depends on which symptom you look at.

What the reviews found

Four reviews have pooled the diosmin and flavonoid trials. They agree on bleeding and disagree on almost everything else.

The Cochrane review

The Cochrane review of phlebotonics for hemorrhoids is the largest. It compared the pills with a control in 20 trials with 2,344 people ¹. The pills lowered the odds of bleeding (odds ratio 0.12), itching (odds ratio 0.23), and discharge and leakage (odds ratio 0.12), and they raised the odds of overall improvement (odds ratio 15.99) ¹. Pain leaned the same way but missed statistical significance ¹. After hemorrhoid surgery, the pills also lowered the odds of bleeding ¹.

The authors called this a potential benefit, noted few safety concerns, and warned about methodological limits in the trials ¹.

The reviews that urge caution

A 2006 meta-analysis of 14 flavonoid trials found the risk of symptoms not improving fell by 58 percent, with apparent drops in bleeding, persistent pain, itching and recurrence ². The same authors then said that weak trial quality, results that varied from trial to trial, and possible publication bias (unflattering trials staying unpublished) raised questions about those benefits ².

The 2018 review of the purified diosmin and hesperidin formula was stricter. It included 10 randomized trials with 1,164 people and graded the quality of each result ³. Three pooled trials favored the pills for bleeding. No other outcome was clearly better than placebo, and the authors rated even the bleeding result as low quality ³.

A 2020 review limited to the same formula pooled four studies and reported less bleeding and leakage and more overall improvement, judged by both patients and doctors ⁴. Pain again only trended lower ⁴.

Single trials worth knowing

Two trials show what a flare on diosmin looks like day to day.

In a triple-blind trial of 134 people in an acute flare, a mix of diosmin, troxerutin and hesperidin reduced pain and bleeding compared with placebo, and fewer people still had swelling or clots after 12 days ⁵. By day 6, the flavonoid group took fewer paracetamol tablets ⁵.

In an older double-blind trial, 100 people with grade 1 or 2 internal hemorrhoids all took a bulk laxative, and half also took diosmin ⁶. The diosmin group looked better on exam at day 4, but by day 14 the two groups were no longer different ⁶. That fits the idea that diosmin speeds up the first days of a flare, while fiber does the slower work.

Does diosmin stop hemorrhoids coming back?

Maybe a little, and the research is thin. The 2006 meta-analysis found fewer recurrences with flavonoids (relative risk 0.53), under the same quality warning as its other results ². A 2023 review of recurrence found that most studies reported recurrence rates of 20 percent or less after surgery or phlebotonics, and found no real-world studies of recurrence after pill treatment alone ⁷. Some of that review’s authors worked for Servier, the company behind Daflon ^6,7.

What holds up better for prevention is fiber. In seven trials, fiber cut the risk of bleeding by half and the risk of symptoms persisting by 47 percent ¹³. A diosmin pill does not replace that. If you want the daily plan, start with the hemorrhoid diet and a fiber supplement.

Diosmin after hemorrhoid surgery

This is where flavonoid evidence looks strongest. The 2024 review of flavonoids after hemorrhoidectomy pooled 10 randomized trials with 775 people ⁸. Pain after surgery was lower with flavonoids, and so were the odds of bleeding (odds ratio 0.13) ⁸. The authors called flavonoids promising and said dosing still needs to be standardized ⁸.

If you are booked for surgery, ask your surgeon whether they want you on a flavonoid before or after the operation. What the weeks after surgery look like is in hemorrhoidectomy recovery, week by week.

How diosmin was taken in the trials

Most trials used the purified diosmin and hesperidin formula, started it during a flare, and kept it going for one to two weeks. Several used a higher dose for the first few days, then dropped to a lower dose ⁶. Others ran it for weeks around surgery ⁸.

In the US, diosmin is sold as a dietary supplement, so the label decides what is in the bottle. Some products match the trial formula and some use different mixes or amounts. Follow the dose on the label you buy, and do not stack two flavonoid products together.

How these two compare with fiber capsules is covered on the best hemorrhoid pills. The wider shelf of pills, creams and pads is reviewed in over-the-counter hemorrhoid treatment.

Diosmin with other plant extracts

Diosmin often shows up in combination products, and two recent trials tested combinations.

In a 2024 randomized trial of grade 1 and 2 internal hemorrhoids, everyone took the purified flavonoid formula, and half also took aescin, the active extract from horse chestnut seeds ¹¹. Bleeding stopped after 2 days with the combination, against 4 days with the flavonoid alone ¹¹. A 2020 trial compared flavonoids with gotu kola (Centella asiatica) and routine care. Bleeding stopped after a median of 2 weeks with either extract, against 3 weeks with routine care, and flavonoids did best on bleeding and irritation ¹².

Those plants, and several others, are graded in herbal supplements for hemorrhoids.

Is diosmin safe in pregnancy?

The best-known study is an open one, with no comparison group. Fifty pregnant women with acute hemorrhoids took the purified formula for a median of 8 weeks before delivery and 4 weeks after ⁹. By day 4, 66 percent had relief from acute symptoms, and the authors saw no effect on the pregnancy, the baby’s growth or feeding ⁹.

That is reassuring, and it is one study of 50 women. A Cochrane review of hemorrhoid care in pregnancy looked at a related flavonoid group, the rutosides, and said they should not be recommended until their safety is clearer ¹⁰. Ask your obstetric provider before you start any flavonoid pill while pregnant or breastfeeding. Fiber, fluids and soaks are the safer first steps covered in hemorrhoids during pregnancy.

Who should skip diosmin or ask first

Diosmin had few safety problems in the trials ¹. Still, ask a pharmacist or doctor first if you:

• are pregnant or breastfeeding
• take prescription medicines
• have a bleeding disorder, or bleeding that is heavy or keeps coming back
• are booked for surgery

MedlinePlus says to contact a clinician if home treatment has not helped after a week, and to get any rectal bleeding checked, because hemorrhoids are only one cause ¹⁴. Colon cancer screening starts at age 45 for adults at average risk ¹⁵. A diosmin pill can make hemorrhoid bleeding settle faster, and it can also hide the clock on bleeding that needs a look. The signs that separate the two are in bleeding hemorrhoids: what is normal and when to see a doctor for hemorrhoids.