The medical marijuana market is supposed to be strictly controlled by the Health Ministry, which instructs which of nine authorized growers each patient can buy from.

But an investigation by TheMarker has learned that about a third of all medical marijuana users, some 8,000 people suffering from cancer, don’t go through the ministry’s Medical Cannabis Unit. The ministry was only able to provide details for 15,000 out of 23,000 authorized users.

The rest are patients in the care of oncologists who are empowered to issue permits to their own patients without ministry intervention, the weak link in a market that is otherwise a strictly controlled chain. The ministry has virtually no information about who the users are or from what conditions they specifically suffer.

Anyone wanting to use cannabis must apply for a permit from the Health Ministry. In order to be approved, the applicant must have one of the medical conditions on the ministry’s list and have a recommendation from a doctor. But cancer patients can go directly to an oncologist from the hospital which is treating them.

With permit in hand, the patient is assigned a supplier and must collect the marijuana directly from the supplier, or use a secure delivery service. The cost is a fixed 370 shekels ($95.50) a month regardless of how much marijuana the patient uses, plus delivery costs if there are any. That adds up to a fairly big business worth tens of millions of shekels annually.

A third of Israel’s 23,000 medical marijuana users are cancer patients and another third suffer from chronic pain. In the first nine months of this year, 2,865 people were approved for permits and another 12,670 for renewals.

But the ministry declined to answer questions by TheMarker as to why patients were not allowed to choose their own supplier. As to the criteria officials used to assign a user to a particular grower, a spokesman offered few details.

“Assigning patients to the nine suppliers is done randomly . Nevertheless, a patient can request to change suppliers and the permit will be transferred,” it said.

But changing suppliers isn’t that easy as one cancer patient discovered when she was assigned a supplier by the ministry’s unit but was unhappy with the service. When her family asked the ministry to switch suppliers, she was told it was only possible after a new permit was issued, a process that would take a week to 10 days. The ministry refused to provide a list of the nine authorized growers.

In any case, a breakdown of market share by the nine suppliers to known medical marijuana users found the divisions didn’t appear at all random.

Tikkun Olam, the oldest of the suppliers, accounted for 27.7% of the market; the others were 2.7% and 12.4%. The ministry responded that patients preferred Tikkun Olam and often asked to switch and make it their supplier.

Tikkun Olam said patients often preferred its products because it offered nursing services and because its cannabis has higher levels of the active ingredient CBD.

The ministry said that the complicated and rigid structure of the market would be changing as soon as there is a level of standardization of cannabis products, at which point they would become available at pharmacies.

“When there are standardized products they will be available at pharmacies and doctors will be able to prescribe products to patients according to dosages in the prescription in the same way as other dangerous drugs like morphine and opiates,” the ministry said.