Hello CS
Thank you for your question again. Most manufacturers will recommend not to use leftover fillers as there is always a risk of contamination. However it is still a common practice in Singapore as some doctors will leave a bit of filler after the initial injection for touch up during the review session.
Personally I feel that it is acceptable to use leftover fillers as long as the clinic stores it properly to lower the risk of contamination. I will also try to finish using the product within 6 weeks. Hope this helps!
Regards,
Dr Jiwei Wu
