Can I put on horsechestnut cream on my legs after sclerothopy. I had it done 1week ago?

It is possible, but depends on a variety of factors such as the level of irritation still present from the procedure, as well as the components of the cream. In general, this is a question best discussed with your treating physician after a physical exam.

I recommend 2 creams after sclerotherapy, Scleroquin to reduce hyperpigmentation and Omega Cream which contains Aescin (horse chestnut extract). See the link below for more details. 

Horsechestnut is one of many natural products that is purported to improve vein health. There should be no contraindication to applying it to your legs one week after sclerotherapy provided the sites treated are now healed.