CHICAGO (CBS) — It has been six months since Illinois began selling marijuana for adult use, and though sales have been rising, some products can be in short supply.

As CBS 2’s Vince Gerasole reported Tuesday night, medical marijuana patients are among those feeling it most.

Since becoming legal at the beginning of the year, adult-use marijuana sales have been strong. Adult sales in January totaled $39.2 million, and by June, the monthly total reached $47.6 million.

But the industry may still be suffering through some growing pains, and medical marijuana patients anecdotally say they can feel it.

“There are still few options for flower within the dispensary,” said medical marijuana advocate Kalee Hooghkirk. “The concentrates, of course, are really, really low as well.”

Illinois law requires dispensaries set aside an adequate supply of marijuana for medical use.

But Jeremy Unruh, a senior vice president at PharmaCann, said the meaning of “adequate” in this case may be fuzzy.

The amount is tied to the number of registered medical patients as of last summer. In June 2019, they totaled roughly 77,000, while by June of this year, their numbers had grown to almost 122,000.

The owners of independent dispensaries like The Herbal Center will tell you in early 2020, finding a deep variety of products to sell was challenging.

“It was a stressful time for everyone to be able to ramp up,” said Michael Mandera of The Herbal Center.

For patients, the issue isn’t a lack of product, but a lack of the right product. If flowers are in short supply, an edible may not be as helpful, according to Hooghkirk.

“People rely on specific methods of consumption for their condition, and if it’s not available, they’re not finding the relief that they need,” she said.

Unruh said Illinois is indeed having supply issues.

His company, PharmaCann, operates both grow houses and dispensaries. He admits shortages are tied to a tenfold increase in demand, and the time it’s taking to build new cultivation centers.

“The capacity, the ability to grow enough cannabis to serve that marketplace, hasn’t yet caught up to meet that,” Unruh said.

Unruh said almost everyone of the state’s 20 cultivators has a grow house coming on line in the next two months, which should hopefully relieve a strain on the system – especially for medical users.

“We all want to supply Illinois patients with the products and medicines they want,” Unruh said.