Sclerotherapy is the injection of a sclerosing liquid into the vein, that causes the vein walls to become "sticky". The vein walls will stick together, blood will stop flowing through the treated vein, a thin fibrous cord is formed and your body will naturally absorb the vein. Sclerotherapy is one of the oldest methods of treating varicose and spider veins. Modern sclerotherapy is well suited to treat spider veins and small reticular veins below the level of your heart. Treating larger varicose veins requires the sclerosant to be delivered by catheter under ultrasound guidance and remains less effective than vein ablation procedures These larger varicose veins are best treated by endovenous radiofrequency ablation. Sclerotherapy is particularly well suited to spider veins of the lower leg and ankle, where surface laser treatment is often less effective. Sclerotherapy is an office based procedure and takes 10-30 minutes to complete. You need to wear a compression bandage or stocking afterwards for a few days.
Sclerotherapy or spider vein treatment is an office based procedure and takes 10 - 30 minutes to complete. While lying on an examination table, the treatment area of your legs will be cleansed with an antiseptic solution. The needles that are used for reticular and spider vein removal are very small, in fact the smallest available needle. A special skin illuminating device is used to illuminate the skin from beneath, allowing the sclerotherapist to locate even the tiniest veins as well as hard-to-find deeper reticular veins that serve as feeder veins for superficial thread or spider veins. The technique is known as transilluminated Sclerotherapy because the device transilluminates the skin making it translucent. Effective treatment of reticular feeder veins may improve the cosmetic result and reduce residual visible veins. Surface laser treatments act on the visible veins at the skin surface and do not address these deeper feeder veins, which is one reason results can be disappointing when the feeder veins are left untreated. Bring short pants to wear during your treatment and loose fitting long pants or a skirt for afterwards.
Your assessment is performed by Dr Johan Blignaut and includes duplex mapping before treatment is recommended. Treatment is selected according to your venous anatomy, not simply according to the veins visible on the skin.
Tell us if you take aspirin, clopidogrel, warfarin, rivaroxaban or any other anticoagulant or antiplatelet medication. Do not stop prescribed medication unless specifically instructed to do so by your doctor or treating team. These medicines can increase bruising after sclerotherapy, but that is usually a minor and acceptable trade-off, and any change to them has to be a medical decision made with the doctor who prescribed them. Please also tell us about over-the-counter anti-inflammatories and supplements such as arnica, fish oil or high-dose vitamin E, which can have a similar effect. Avoid all tanning. Shaving or waxing your legs is a good idea, but do it at least a day or two in advance. On the day of your appointment, bring short pants to wear during treatment and long loose fitting clothing for after treatment. Afterwards avoid heavy lifting, strenuous exercise and hot baths for 2 days. Daily walking is very good and you are encouraged to walk at least 45 minutes every day for a couple of weeks. Compression therapy in the form of class 2 stockings will be provided afterwards and will improve results.
Foam sclerotherapy is a mix of the sclerosant chemical and air, to produce a foam, that is injected. This is suitable for the treatment of bulging varicose veins or large veins.
Cosmetic sclerotherapy is a liquid based sclerosant solution that is injected into fine reticular and spider veins.
Men and women of all ages who are suffering from unsightly spider veins and reticular veins(slightly larger blue veins) are good candidates for sclerotherapy. If you are pregnant or breastfeeding, it is advisable to postpone your sclerotherapy, as safety is not established. Read more on varicose vein management during pregnancy Many pregnant women experience dramatic and spontaneous improvement in the months following delivery, making their treatment simpler, and sometimes unnecessary. Patients who have an allergy to the sclerosant or who have a deep vein thrombosis (DVT) are not suitable candidates. Sclerotherapy has a well established place in modern practice, principally in the treatment of spider veins and their reticular feeder veins, and of residual or recurrent veins following other treatment.
Dr Blignaut will examine your legs, review your medical history and the severity of your condition to determine the best spider vein treatment procedure, or combination of treatments, for you.
In expert hands, sclerotherapy is very safe. Serious side effects like DVT, allergic reactions and skin ulceration are rare. More common side effects of sclerotherapy are mild and temporary, these include:
Cosmetic sclerotherapy for spider veins is not generally funded by medical schemes in South Africa, and is payable by the patient. Current session pricing is available from our reception teams at any of our centres.
Cosmetic sclerotherapy is performed by registered nurse sclerotherapists trained by Dr Blignaut, and is billed per session. Foam sclerotherapy is a different treatment, is performed by Dr Blignaut, and may be medically indicated in some patients; pricing is available on request and a consultation is required beforehand.
For more on how funding works, see our medical schemes and pricing page, or contact your nearest vein centre.
Not sure which treatment is right for you? See our side-by-side comparison of radiofrequency ablation, EVLA, VenaSeal and foam sclerotherapy, and how the choice is made.
Written and medically reviewed by Dr Johan Blignaut, MBChB (UOFS), FCS(SA), Specialist Surgeon.
Last medically reviewed: August 2026. This page is reviewed periodically and updated when clinical practice changes. It is general information, not medical advice – see our terms and medical disclaimer.