The government says it will reach a decision within the next few weeks on whether laws around medical cannabis will be changed.
The Advisory Council on the Misuse of Drugs is now assessing the "balance of harms and public health needs" in terms of rescheduling treatments.
It comes after high profile cases involving children with severe epilepsy being denied access to cannabis oil.
Cannabis for recreational use will remain illegal.
The first part of the review - looking at the scientific evidence - has already been completed by England's chief medical officer.
Prof Dame Sally Davies said there was conclusive evidence of therapeutic benefit of prescribing cannabis-based products for certain medical conditions.
That list includes treating:
- chronic pain
- nausea and vomiting caused as a side-effect of cancer therapies such as chemo
- muscle spasticity symptoms in multiple sclerosis (MS) patients
Overall, the report found less evidence for the treatment of epilepsy.
The Home Office recently granted Billy Caldwell and Alfie Dingley, boys who have rare forms of epilepsy, a short-term licence to allow them access to cannabis oil, which their parents say helps to control their seizures.
An epilepsy drug called Epidiolex is currently going through the process of authorisation and is being assessed by the European Medicines Agency for the treatment of childhood epilepsy.
It contains a compound found in cannabis called CBD and is exempt from scheduling regulations. US regulators have already approved its use.
There are cannabis-based medicinal products currently available in the UK. Sativex, which contains both CBD and the principal psychoactive component of cannabis THC and is used to treat MS, is listed as a Schedule 4 drug.
Raw cannabis and THC are controlled as Schedule 1 drugs as there is currently no recognised medicinal or therapeutic benefit in the UK.
Dr Michael Bloomfield, Clinical Lecturer in General Psychiatry at University College London, welcomed the review saying: "It could help patients suffering from devastating illnesses and facilitate medical research into new potential treatments for a range of disorders."