For months, Advanced Grow Labs LLC — one of Connecticut's four medical marijuana growing companies — slogged through the process of competing for a state license, securing local zoning approvals, and outfitting a building to state regulations that are as a tough as those at any pharmaceutical manufacturer.

Now, managing partner David Lipton knows his West Haven company is getting close: He planted his first marijuana seeds almost three weeks ago.

"I did my own tray, the D.L. tray," Lipton said last week. "My tray is looking pretty good; they're about 3 or 4 inches high now. Finally, we're not just buying stuff, we're dealing with something that grows."

Nearly two years after the state legalized it, the first medical marijuana is expected to go on sale next month. About 2,000 residents with qualifying chronic illnesses have registered with the state and with one of Connecticut's six dispensaries.

The four medical marijuana manufacturers are at varying stages of growing pot. It remains unclear which company will be the first to market, turning the raw plant into medicine that is smoked, used in a vaporizer, eaten or rubbed on.

Connecticut's six licensed dispensaries have fielded calls from potential clients for months, and at least one has passed the final state inspection and is consulting with clients to map out treatment plans with pharmacists on its staff.

In South Windsor, Prime Wellness of Connecticut last week met with as many as 50 people suffering with some of the 11 illnesses covered under the law.

"There are patients that are really, really in need, and so they have been waiting for two years," said Tom Nicholas, chief executive of the Prime Wellness dispensary. "We're almost at the end of the tunnel, but not quite."

The passage of the law in Connecticut did not come without controversy. Opponents raised concerns that once the medicinal marijuana left the dispensary, it could get into hands of those for whom it wasn't intended.

Pro-medical marijuana groups now say they are thrilled that pot will soon be available for the sick. But they also are worried that the state's stringent regulations — including on that requires every batch of processed marijuana be tested for purity — will drive up costs and make it unaffordable for some, at least at first.

As exciting as it is watching his tray of plants grow, Lipton said he doesn't have much time to relax.

AGL's manufacturing plant on Frontage Road is still under construction, with the plants growing only in a small, state-approved test area. He knows he won't be the first supplier to dispensaries but he wants to have his marijuana in all six. He's coming up against three competitors: Connecticut Pharmaceutical Solutions LLC in Portland, Curaleaf LLC in Simsbury and Theraplant LLC in Watertown.

"Until we are out there selling and bringing in revenues," Lipton said, "we're not out of the woods."

Prices To Be Determined

When the state legislature legalized medical marijuana in 2012, it ended a wide-ranging sale ban in Connecticut that dated back more than 80 years.

Regulations written by the state Department of Consumer Protection allow a broad array of products — including what can be smoked; tinctures, creams, and oils; and baked goods, such as brownies, bars and cookies. Marijuana-infused beverages and candy are not permitted under the regulations.

Before a patient can register with the state, a doctor must certify that he or she has a qualifying chronic condition with symptoms that could be eased by marijuana The doctor also certifies how much marijuana the patient is allowed a month, with a maximum of 2.5 ounces. Then a plan of treatment is worked out with the pharmacist in a consultation at the dispensary.

What isn't yet known is how much the medical marijuana will cost users, with growers saying it is still too early to predict their pricing to the retail dispensaries. The costs are all out-of-pocket to the patient because medical marijuana is not covered by insurance.

"It really depends on the market and the regulations," said Chris Walsh, editor of Marijuana Business Daily, based in Rhode Island. "Connecticut is probably going to be higher. It costs a lot more to get started there than in other states."

In Maine, the wholesale cost for a gram of medical marijuana ranges from $6.50 to $8.50 and rises to $12 to $13 when it is sold to patients, Walsh said.