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Treatment Overview

Sclerotherapy uses an injection of a special chemical (sclerosant) into a varicose vein or spider veins. The injection damages and scars the inside lining of the vein. This causes the vein to close.

During this procedure, the affected leg is propped up to drain blood. Then the sclerosant is injected into the varicose or spider vein. This is done in a doctor's office or clinic. It may take about 15 to 60 minutes. How long it takes depends on how many veins are treated and how big they are.

After the injection is given, pressure is applied over the veins. This is to prevent blood returning to the veins when you stand up. You may need to wear compression bandages or stockings after the procedure. Your doctor will tell you how long to wear them.

Sclerotherapy may be painful. The shot of sclerosant can cause a feeling of burning or cramping for a few minutes in the area where the shot was given. You may need repeated sessions and many injections each session. It depends on how bad the varicose and spider veins are and what type of sclerosant is used.

Another technique allows your doctor to inject sclerosant with a catheter. This is sometimes called endovenous ablation. The catheter and sclerosant are guided to the affected vein with the help of duplex ultrasound. This process allows sclerotherapy treatment to be used on larger varicose veins.

What To Expect

For most people, sclerotherapy doesn't require any recovery period. After the treatment, you will likely be able to walk right away. Avoid strenuous exercise until your doctor says it's okay. This may be for 2 weeks. Walk every day for at least 10 minutes. Try not to sit or stand for long periods of time.

For the first 2 weeks after the procedure, avoid exposing your legs to the sun.

You'll probably have to wear compression bandages or stockings after the procedure. Your doctor will tell you how long to wear them. This may be at least 1 week.

Why It Is Done

Sclerotherapy is used to treat:

  • Spider veins and small veins that aren't causing more serious problems.
  • Varicose veins that may or may not be causing symptoms.

It may be done on its own or as a follow-up to another procedure or surgery.

Learn more

How Well It Works

Sclerotherapy may reduce symptoms and improve the look of the skin. It seems to work in more than 70 out of 100 people. It might not work for up to 30 out of 100 people who have the procedure.footnote 1


The risks of sclerotherapy include:

  • Skin color changes along the treated vein.
  • New spider veins.
  • Itching, bruising, pain, and blistering where the veins were treated.
  • Scarring from ulcers or death of the tissue around the treated vein (skin or fat necrosis). This can happen if sclerosant is injected outside a vein or if sclerosant escapes through the wall of a weakened vein.
  • A mild or severe (anaphylactic) reaction to the sclerosant. (Severe reaction is very rare but can be life-threatening.)
  • Blood clots or damage in the deep vein system.



  1. Whing J, et al. (2021). Interventions for great saphenous vein incompetence. Cochrane Database of Systematic Reviews, (8). DOI:10.1002/14651858.CD005624.pub4. Accessed August 30, 2022.


Current as of: August 6, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.


PeaceHealth endeavors to provide comprehensive health care information, however some topics in this database describe services and procedures not offered by our providers or within our facilities because they do not comply with, nor are they condoned by, the ethics policies of our organization.