Sclerotherapy: A Minimally Invasive Treatment for Varicose and Spider Veins
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is sclerotherapy?
Sclerotherapy is a medical procedure that treats varicose veins and spider veins, usually on the legs, by injecting a liquid or foam solution into the vein with a very fine needle. The solution irritates the vessel lining so it scars and closes, and the vein gradually fades. Full results can take weeks or months to appear. [1]
What the research says
Skin staining is a common side effect and rises with sclerosant strength. A systematic review of 27 reports on polidocanol sclerotherapy found hyperpigmentation in 2% to 25% of treatments of spider and reticular veins with 0.25% polidocanol, 12.5% to 67.9% with 0.5%, and 13% to 73% with 1%. Staining lasting more than 6 months was reported in up to 7.5% (Bossart et al., J Eur Acad Dermatol Venereol, 2023). [2]
Results build over weeks to months. In a randomized trial of 30 people with leg reticular veins treated with foam polidocanol, mean improvement reported by participants and a blinded investigator was 0% to 50% at day 21 and 26% to 75% at day 90. Two different polidocanol-to-air ratios were similarly safe and effective (Hoss et al., Dermatol Surg, 2020). [3]
What Is Sclerotherapy?
Sclerotherapy is an in-office treatment for varicose veins and spider veins. Once the vein is closed, blood is rerouted to healthier veins and the treated vein is gradually absorbed. The chemical and the amount used are chosen based on the size of the vein being treated. [1]
How does the sclerotherapy procedure work?
Sclerotherapy may start with a test injection and ultrasound mapping to find the right veins, then the area is cleaned before the solution is injected. [1]
Step | Action | Purpose |
|---|---|---|
Test injection | Your provider may try a test injection first. | Checks that you do not react to the solution. |
Mapping | Ultrasound may be used to find the right veins. The largest veins are treated first. | Helps deliver the solution precisely. |
Cleaning and stretching | The area is cleaned with alcohol or another disinfectant and the skin is stretched around the injection site. | Keeps the area free of germs and helps the needle reach the vein. |
Injection | A very fine needle delivers a liquid or foam solution directly into the vein. | Irritates the vein lining to start closure. |
Monitoring | You may lie down for about 15 minutes afterward. | Makes sure you do not have a bad reaction. |
Who Can Have Sclerotherapy?
Sclerotherapy is not for everyone. Before the procedure you will meet with a vascular specialist who can help you decide if it is right for you. [1]
Situation | Guidance |
|---|---|
Active blood clot in a vein | Not an option (see our guide to blood clots below). |
Pregnancy or breastfeeding | Not an option. |
Unable to get out of bed | Not an option. |
Past blood clot | May still be possible, depending on what caused the clot and how serious it was. |
Veins needed for future surgery | In most cases your provider will not treat a vein you might need later, such as the saphenous vein for heart bypass surgery. |
To learn more about clotting problems, read our guide to blood clots.
How should you prepare for sclerotherapy?
Before sclerotherapy, ask your provider about certain antibiotics, anti-inflammatory medicines and prednisone, and on the day skip leg lotion and bring shorts. [1]
Antibiotics such as tetracycline or minocycline: They may stain your skin if you take them 7 to 10 days before or after treatment. [1]
Aspirin, ibuprofen, and other anti-inflammatory medicines: They may interfere with the injected substance or make you bleed more. [1]
Prednisone: It can keep the injected substance from working as well as it should. [1]
On the day: Do not put lotion on your legs, and bring a pair of shorts. Bring any compression stockings you already have so your provider can check they give enough support. [1]
What is the sclerotherapy treatment experience like?
Sclerotherapy is done in your provider's office and takes about 30 to 45 minutes. You will feel the needle pinch and possibly a mild burning feeling. In larger veins you may feel cramping for a minute or two during the injection. The number of veins treated in one session depends on their size and location and your overall health. [1]
What are recovery and aftercare like after sclerotherapy?
Recovery is quick. You can drive home and get back to your normal activities, and walking is good for your recovery. [1]
Compression Therapy
Wear support stockings or compression wraps for three to seven days to press the treated vessels together. Regular stockings from a retail store may not work. [1]
The First 48 Hours
Avoid aspirin, ibuprofen, and other anti-inflammatory medicines. You may take acetaminophen for pain relief. [1]
Do not take hot baths or sit in a whirlpool or sauna. Showers are fine, but use cooler water than usual. [1]
Wash the injection sites with mild soap and lukewarm water. [1]
Do not apply hot compresses or any form of heat to the treated areas. [1]
Avoid direct sunlight, including sun tanning and tanning beds. [1]
You will most likely have a follow-up visit a month or two after treatment. If you are having multiple treatments, the next session is usually two or three months after the first. [1]
What are the results, benefits and risks of sclerotherapy?
A session may get rid of an estimated 50% to 80% of injected veins. Spider veins usually respond in three to six weeks, while larger veins can take three to four months. If treatment does not work, your provider can try different solutions or another method such as laser therapy. Results are not instant, so it helps to talk with your provider about what to expect. [1]
Benefits: No anesthesia is needed, results come fairly quickly for small veins, and when treatment works the problem does not come back, although new varicose veins may form. [1]
Common side effects: Lumpiness or hardness of larger veins for several months, redness for a few days, brown lines or spots that usually go away within three to six months, bruising, tiny new blood vessels that fade within a few months, and rarely an allergic reaction. [1]
Other risks: Infection, blood clots, and inflammation. Sclerotherapy also takes longer to work than surgery. [1]
Call your provider right away if you have inflammation within 5 inches of your groin, sudden leg swelling, small ulcers at an injection site, or red streaking, especially in the groin area. Call 911 if you have sudden shortness of breath, chest pain or cough up blood, which can be signs of a blood clot in the lungs. [1]
Laser treatment (endovenous thermal ablation) is another option, but it is difficult on veins with many twists and turns. Your provider will weigh how your veins look when choosing the best treatment. Some insurance companies cover sclerotherapy for specific medical conditions. [1]
Conclusion
Sclerotherapy is a quick, minimally invasive way to treat varicose and spider veins, especially smaller ones. Knowing what to expect, including the weeks or months it takes to see results, and following your provider's instructions before and after the procedure give you the best chance of a good outcome.
What are the next steps if you are considering sclerotherapy?
If you are considering sclerotherapy, schedule a consultation with a vascular specialist to discuss your goals and medical history. Prepare a list of your medications, since some may need to be paused. After treatment, keep walking and wear your compression stockings as directed.
Frequently Asked Questions
How long does a sclerotherapy session take?
About 30 to 45 minutes. The number of veins treated depends on their size and location and your overall medical condition. [1]
Is sclerotherapy painful?
Most people feel a needle pinch and possibly mild burning. In larger veins you may feel cramping for a minute or two during the injection. [1]
Can I drive home after treatment?
Yes. You can drive home and get back to your normal activities. Walking is good for your recovery. [1]
How many sessions will I need?
It depends on how many veins you have and how they respond. If you need more than one session, the next one is often two or three months after the first. [1]
Will treated veins come back?
When treatment works, the treated vein does not become a problem again. New varicose veins can still form over time and may need treatment. [1]
When will I see results?
Spider veins usually respond in three to six weeks. Larger veins can take three to four months. [1]
Do I have to wear compression stockings?
Yes, for three to seven days. Regular support stockings from a retail store may not work, so ask your provider what to use. [1]
Can I exercise after the procedure?
Walking is encouraged. Ask your provider which other activities are safe and for how long. [1]
Which medications should I avoid?
Ask your provider before treatment about aspirin, ibuprofen and other anti-inflammatory drugs, prednisone, and the antibiotics tetracycline and minocycline. [1]
Can I have sclerotherapy if I am pregnant?
No. It is not an option during pregnancy or breastfeeding. [1]
What are the common side effects?
Lumpiness or hardness, redness, brown lines or spots, bruising, and tiny new blood vessels. Most fade over days to months. [1]
Is sclerotherapy covered by insurance?
Some insurance companies cover it for specific medical conditions. Check with your insurer and provider.
Can I use lotion on my legs?
No. Do not put lotion on your legs before or after treatment. [1]
What should I wear to my appointment?
Bring a pair of shorts. If you have compression stockings from past treatments, bring them too. [1]
What are the warning signs of a complication?
Call your provider right away for inflammation within 5 inches of your groin, sudden leg swelling, small ulcers at an injection site, or red streaking, especially near the groin. [1]
Related Reading
What Are Varicose Veins? A Plain-Language Guide to the Bulging, Twisted Veins That Most Often Show Up on the Legs explains why varicose veins form and the treatment options.
Understanding Polidocanol Injection: Treatment for Varicose Veins describes a common sclerotherapy medicine and how it is used.
Endovenous Thermal Ablation: Procedure, Recovery, and Risks explains heat-based closure for larger problem veins.
Chronic Venous Insufficiency (CVI): What It Is, Why It Happens, and How It Gets Treated covers the faulty vein valves behind leg swelling and varicose veins.
References
Cleveland Clinic. Sclerotherapy. Cleveland Clinic. March 6, 2026. https://my.clevelandclinic.org/health/treatments/6763-sclerotherapy
Bossart S, Daneluzzi C, Cazzaniga S, et al. Skin hyperpigmentation after sclerotherapy with polidocanol: a systematic review. J Eur Acad Dermatol Venereol. 2023;37(2):274-283. PMID 36196455. https://doi.org/10.1111/jdv.18639
Hoss E, Kollipara R, Boen M, et al. Comparison of the safety and efficacy of foam sclerotherapy with 1:2 polidocanol to air ratio versus 1:4 ratio for the treatment of reticular veins of the lower extremities. Dermatol Surg. 2020;46(12):1715-1720. PMID 32947299. https://doi.org/10.1097/DSS.0000000000002709
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or treatment. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.
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