The last commercial producer licensed to produce green muscle is/was Becker Underwood in South Africa, which was taken over by BASF in 2012. I don't know if it is still available.
There is a new producer, Eléphant Vert. The holding is based in Geneva, but they have a factory in Meknès, Morocco. Write to Benoit Gossaert ([email protected]) to find out how to obtain the product.