The Effectiveness of Sclerotherapy
In general, spider veins respond in 3 to 6 weeks, and larger veins respond in 3 to 4 months. If the veins respond to the treatment, they will not reappear. However, new veins may appear at the same rate as before. If needed, you may return for injections.
Studies have shown that as many as 50% to 80% of injected veins may be eliminated with each session of sclerotherapy.
Less than 10% of the people who have sclerotherapy do not respond to the injections at all. In these instances, different solutions can be tried. Although this procedure works for most patients, there are no guarantees for success.