“You have what’s called the ‘entourage effect’, which is basically the tail of what’s in the plant and can actually be quite important,” he says. “Frankly, there’s a lot more research work to be done.”
And therein lies the conundrum of the medical cannabis market. Most drugs undergo strict testing, usually in the form of randomised control trials (RCTs) before legalisation. Cannabis, on the other hand, was legalised before the usual battery of such trials. And doctors, used to prescribing standardised drugs in standardised doses, appear to be uncomfortable about issuing patients the new drugs.
The result is that, at present, only a few thousand patients are using medical cannabis. The vast majority of these are prescriptions through private doctors that can cost up to £2,000 per month (Mr Langley says the average cost to the 2,000 patients using Grow’s pharmacy is “less than £500 per month”).
Severe childhood epilepsy, which can involve hundreds of seizures each day, is one of several conditions for which advocates say cannabis medicines offer “life-changing” benefits. Yet so far, just three affected families have received free NHS prescriptions. Almost two dozen others are paying.
One drug that has been authorised for NHS prescriptions, Epidoylex, contains only CBD, which some parents say is not enough to control seizures. The Department for Health and Social Care insists “more evidence is needed to routinely prescribe and fund other treatments on the NHS”.
Such evidence, says Mr Langley, has traditionally taken the form of RCTs, though he says Nice (the National Institute for Clinical Excellence) “do accept real-world evidence, which I think is probably the bigger opportunity with cannabis”.
It is this switch from blind trial data to “anecdata” – testimony from patients – that is proving hard for some in the medical establishment to swallow. However, Langley insists its potential as a “multiple-compound medicine” means cannabis defies the usual assessment.
“What the Government wants, what Nice wants, is for us to look exactly like pharma has always looked like. To be honest, that’s a bit of a cop out.”
Grow is working, he says, “to educate” doctors so they may in future be less wary. He predicts that, given medicine is a highly-networked profession, a few conversions will lead to “exponential” uptake.
That is one strand of the Grow business. Its others are based on Mr Langley’s experience as a commodities trader or, as he puts it: “Essentially wholesale import/export of [cannabis] oils from Colombia to Germany, say.”