Is it permissible to run a cannabis clinic?

Dear questioner,
Thank you for your important question.
May Allah, Most High, reward you for your desire to increase in knowledge.
As for using recreational marijuana, it is impermissible and prohibited.
As for using medical marijuana, it is permissible with the following conditions:
  1. A qualified physician that is a pious Muslim informs the patient that the medicine can effectively treat the illness, based on the high likelihood of near certainty.
  2. No lawful alternative medicine is available or sufficiently effective;
(c) It is used only for the need, and no more.
Please see:
As for selling recreational marijuana, it is impermissible and prohibited. This is due to the principle: “That which is prohibited from using is prohibited from selling.”
As for selling medical marijuana through a legal dispensary, this is a new issue that needs more clarity and research.
At the moment, we would say that it is impermissible. This is due to the absence and unclarity of many of the conditions required in consuming medical marijuana. Here are some considerations:
The majority of the customers and physicians are not Muslim (i.e., they do not follow Islamic guidelines.) A condition for consuming medical marijuana is that the physician who writes the prescription must be a pious Muslim or (in the absence of a pious Muslim) an upright physician who appreciates the Sacred Law’s importance.
The customer may have alternative options which are lawful. In this case, it would be impermissible to sell to this individual.
Many individuals are obtaining medical marijuana cards that allow them to purchase it well beyond their need. In this case, it would also be prohibited to sell.
(Ibn Abidin, al-Hashiya/ Zuhayli, Qawaid al-Fiqhiyya)
And Allah alone knows best,
[Ustadh] Omar Popal
Checked and Approved by Shaykh Faraz Rabbani