Hair regrowth serums - advice please!

Hi lovely people!
I am reading that rosemary based serums can help with hair regrowth after chemo.  Does anyone have any experience/advice on using these?  How long after my last treatment should I leave it before starting to use?  Any advice gratefully received!  Many thanks!

Ckaye I waited till after chemo and rads completed before using anything but when I did I used sunny isle extra dark Jamaican black castor oil, rubbed it on scalp left for hour then washed off with the lush red dot shampoo bar called new (not sure if they still do it)? And continued to do this and it got my hair back well remember to get mascara back on lashes too the moment the start growing back helps to train them to curl up again and not grow out straight, the little mascara tester brushes the beauty counter girls use are the best :two_hearts: :two_hearts: :sparkles: :sparkles: Shi xx