Any healthy substance in overdose might produce adverse effect so please be carefull with that high dose
Also you can try topical tocotrienols/tocopherols for hair loss. I'm planning to do it in near future because of this study
https://www.ncbi.nlm.nih.gov/pubmed/28803863 (4-fold induction in β-catenin but study was done on mice... ) and also had another study somewhere that use only gamma-tocotrienol or gamma-tocopherol(dont remeber which one) which also produce surprising effect on hairgrowth.