Hemorrhoids & Veins · Medication Guide
Diosmin in Thailand
What diosmin is, how well it works for hemorrhoids and chronic venous disease, its side effects, and how men in Bangkok get it safely. A flavonoid venotonic for the heaviness, swelling and bleeding that desk-bound workers know too well. Reviewed by a licensed physician at a MOPH-registered men's health clinic.
- Relief within days for flares
- Thai FDA registered · pharmacy medicine
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Medically reviewed by Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic
Last reviewed
11 July 2026
1,000 mg
Typical daily dose
two 500 mg tablets a day
67%
Lower bleeding risk
flavonoids vs control in hemorrhoid trials
7 days
Acute flare course
higher dose for the first week
2×/day
How it's taken
one tablet, morning and evening
Key takeaways
Diosmin is a flavonoid venotonic that improves vein tone and reduces the swelling, bleeding and discomfort of hemorrhoids and chronic venous disease.
In a meta-analysis of hemorrhoid trials, flavonoids lowered the risk of bleeding by about 67% and roughly halved the chance of persistent symptoms.
It manages symptoms. It does not shrink large varicose veins or replace a procedure for advanced piles, so a doctor should confirm the cause first.
Diosmin is sold widely in Thai pharmacies, but leg swelling and rectal bleeding can signal serious conditions, so an assessment matters before self-treating.
01
What diosmin is & how it works
Diosmin is a flavonoid, a natural plant compound, used as a venoactive medicine, a venotonic, to treat the symptoms of chronic venous insufficiency and hemorrhoidal disease. It is often paired with a related flavonoid, hesperidin, in a micronized combination.
Veins rely on firm walls and one-way valves to push blood back up against gravity. When the walls weaken and the valves start to leak, blood pools, pressure builds, and fluid seeps into the surrounding tissue. In the legs that means heaviness, cramps and swelling. In the anal cushions it means the swollen, inflamed vessels we call hemorrhoids. Diosmin raises venous tone, reduces the leakiness and fragility of small blood vessels, improves lymphatic drainage, and calms the inflammation around these vessels.
Long office hours, long-haul flights, standing shifts, straining on the toilet and Bangkok's heat all raise venous pressure, which is why desk-bound workers see these symptoms so often. Diosmin targets the microcirculation rather than one visible vein, so it eases symptoms rather than reversing the underlying anatomy. Whether it is right for you depends on the cause and severity, which is what the assessment is for.
Blood pools in the veins
Weakened vein walls and leaky valves let blood collect in the legs and the anal cushions.
Pressure and inflammation rise
Higher venous pressure makes small vessels leak fluid and triggers local inflammation and swelling.
Diosmin tightens the veins
It raises venous tone and reduces capillary permeability, so less fluid escapes into the tissue.¹
Swelling and bleeding ease
Better drainage and calmer inflammation reduce heaviness, edema and hemorrhoidal bleeding.²
02
Getting diosmin in Thailand
Thai FDA status
Registered as a modern drug with the Thai FDA. Plain diosmin 500 mg tablets and the micronized diosmin–hesperidin combination, sold in Thailand under brands such as Daflon, are available through licensed pharmacies.³
How Menscape provides it
Menscape dispenses diosmin after a short doctor assessment. That step confirms what is actually causing your bleeding or swelling, so you are not quietly masking a problem that needs different treatment.
Why not just self-treat
Diosmin is low-risk and easy to buy, but self-diagnosis is where people go wrong. Rectal bleeding can come from a fissure, infection or, rarely, bowel disease; new one-sided leg swelling can signal a clot. A doctor rules those out first.
Thai FDA guidance. Flavonoid venotonics are supportive treatments, not cures for venous disease. The regulator warns against buying medicines from unlicensed online sellers, where counterfeit and substandard products are common.⁴
03
Does it work? The evidence
For hemorrhoids, the clearest summary is a meta-analysis of randomized trials of flavonoids, diosmin among them. Pooled results showed flavonoids cut the risk of bleeding by roughly 67% and roughly halved the chance of persistent symptoms, itching and recurrence, though the authors flagged that trial quality varied. Micronized diosmin–hesperidin is the most-studied formulation for acute flares, where a higher dose is used for the first days.⁵
For chronic venous insufficiency, a Cochrane review of phlebotonics concluded these flavonoids probably reduce leg swelling slightly and may ease symptoms such as heaviness and cramps, on moderate-to-low certainty evidence. The honest read: diosmin reliably helps symptoms, but it does not reverse advanced varicose veins or replace a procedure when one is needed.⁶
67%
Lower bleeding risk
flavonoids vs control in hemorrhoid trials
~50%
Fewer persistent symptoms
pooled flavonoid trials, same review
Meta-analysis of randomized trials of flavonoids for hemorrhoids (Alonso-Coello et al., 2006). Trial quality varied and individual results differ.⁵
04
Side effects & who shouldn't take it
Common side effects
Diosmin is generally well tolerated. The most common effects are mild and gut-related: nausea, stomach discomfort and diarrhea. These usually settle and rarely require stopping.
Less common effects
Headache, dizziness and skin rash are reported less often. Stop and seek care if you develop signs of an allergic reaction, such as facial swelling or a widespread rash.
Not suitable for
Not recommended in pregnancy or breastfeeding without a doctor's advice, as safety data are limited. Heavy, dark or persistent rectal bleeding needs proper assessment, not just a venotonic.
Interactions & warnings
Few significant drug interactions are known, but always list your current medicines and supplements. Diosmin supports treatment; it does not replace fibre, hydration, weight management or any procedure your doctor recommends.
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Alternatives & combinations
Oral · often combined
Hesperidin
A companion flavonoid. Micronized diosmin–hesperidin is the most-studied combination for hemorrhoids and chronic venous symptoms.
Topical · symptom relief
Topical hemorrhoid treatments
Creams and suppositories with a local anaesthetic or anti-inflammatory ease itching and pain, and are often used alongside an oral venotonic during flares.
Supportive · leg veins
Compression & movement
Graduated compression stockings, regular walking breaks and leg elevation reduce venous pooling for desk-bound workers. First-line support that pairs well with diosmin.
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How prescription works at Menscape
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Book your consultation today.
Message us on WhatsApp or LINE
A few minutes on your phone: your symptoms, health history and current medicines. It is PDPA-protected.
Doctor consultation
A licensed Thai physician reviews your case by video call or in clinic at Asoke, confirms what is driving your symptoms and rules out anything that needs different care.
Prescription, if suitable
If diosmin is appropriate, the doctor prescribes it and a licensed pharmacy dispenses it for pickup or delivery.
Follow-up
A check-in to confirm your symptoms are improving, with a referral for a procedure if that turns out to be the better route.
The doctor decides. Starting a conversation is not a commitment and does not guarantee a prescription. If diosmin is not right for you, the doctor will explain why and discuss alternatives.
Medically reviewed by
Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic, Bangkok
“Most men put up with hemorrhoids and heavy legs for years before asking. A venotonic like diosmin genuinely helps, but the first job is confirming the cause. Bleeding is not something to self-diagnose.”
- Reviewed
- 11 July 2026
- Next review
- January 2027
- Editorial standard
- Each guide is checked against the Thai FDA label and the primary literature, then reviewed by a licensed physician.
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Frequently asked questions
Can I buy diosmin over the counter in Thailand?
In practice, yes. Flavonoid venotonics like diosmin and diosmin–hesperidin are widely sold in Thai pharmacies and often do not require a prescription. The catch is diagnosis: rectal bleeding and leg swelling have several possible causes, so it is worth a doctor's check before you rely on it.
How fast does diosmin work for a hemorrhoid flare?
For acute flares a higher dose is used for the first few days, and many people notice less bleeding and discomfort within that first week. It eases symptoms rather than instantly shrinking a large hemorrhoid.
Does diosmin cure hemorrhoids or varicose veins?
No. Diosmin manages symptoms such as bleeding, swelling, heaviness and pain. Larger hemorrhoids or advanced varicose veins may need a procedure, which is another reason a proper assessment matters.
How do I take diosmin?
For chronic venous symptoms the usual dose is 1,000 mg a day, taken as one 500 mg tablet twice daily with food. Acute hemorrhoid flares use a higher short-term dose set by your doctor.
Is diosmin safe to take long-term?
It is generally well tolerated and has been used for decades. Side effects are usually mild and gut-related. Your doctor will review whether ongoing use makes sense for your situation.
Can I take diosmin if I'm pregnant?
Discuss it with your doctor first. Safety data in pregnancy and breastfeeding are limited, so it is not recommended without medical advice.
Will diosmin help the heavy, swollen legs I get from sitting at a desk all day?
It can reduce venous heaviness and swelling, and it works best alongside movement breaks, leg elevation and compression stockings. If the swelling is new, one-sided or painful, see a doctor to rule out a clot before relying on any venotonic.
I already take diosmin abroad. Can I continue it in Bangkok?
Yes. It is widely available here, and a local doctor can review your treatment and provide a prescription so you continue without interruption.
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References
1. Servier. Micronized purified flavonoid fraction (diosmin–hesperidin) summary of product characteristics. Accessed July 2026.
2. Ramelet AA. Clinical benefits of a venoactive flavonoid in the most severe stages of chronic venous insufficiency. Angiology. 2001;52(Suppl 1):S49–S56.
3. Thai Food and Drug Administration. Drug registration database, ndi.fda.moph.go.th. Accessed July 2026.
4. Thai FDA (Oryor) consumer warnings on purchasing medicines from unlicensed online sellers, oryor.com. Accessed July 2026.
5. Alonso-Coello P, Zhou Q, Martinez-Zapata MJ, et al. Meta-analysis of flavonoids for the treatment of haemorrhoids. Br J Surg. 2006;93(8):909–920.
6. Martinez-Zapata MJ, Vernooij RWM, Simancas-Racines D, et al. Phlebotonics for venous insufficiency. Cochrane Database of Systematic Reviews. 2020;11:CD003229.
7. Cospite M. Double-blind, placebo-controlled evaluation of clinical activity and safety of a micronized flavonoid in acute haemorrhoids. Angiology. 1994;45(6 Pt 2):566–573.
This guide is educational information, not medical advice. Diosmin should be used under the guidance of a licensed physician, especially when bleeding or swelling is new, severe or persistent.
This guide is part of the Menscape digestive library
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