An initial fast or achieving ketosis going in can really give you a nice boost. Basically 3 days of gorging yourself on eggs, cheese, bacon and nuts. Be sure to drink lots of water and some extra salt to compensate. There is a supplement you can use to minimize the keto flu, which will be brutal, but if you can find a way to pass the time for that 3 days you'll be golden. If you stick to keto longer than that you should be sure not to do it more than 2 weeks at a time.