Using marijuana is becoming more and more acceptable in the United States, both medically and recreationally. Despite more states making its use legal, there is still a stigma around pot, especially in the workplace. So does using marijuana really affect your job performance? A new study finds it all depends on when you use it and consuming marijuana after your shift has no impact on your next day at work.

Researchers from San Diego State and Auburn Universities surveyed 281 employees and their supervisors, looking at the times workers use cannabis products and if managers notice a drop in performance. Although the results show marijuana use before and during the workday decreases performance, supervisors don’t report a drop-off in workers who use it after.

“To our knowledge, this is the first study to research cannabis usage in relation to workplace behaviors in nearly 20 years,” Dr. Jeremy Bernerth of San Diego State says in a university statement.

Measuring marijuana’s effects

The study in Group & Organization Management examines three major areas of work performance. The observational report grades how well subjects handle their job requirements (task performance), their willingness to help colleagues (citizenship behavior), and counterproductive work behavior.

Bernerth and his team asked each employee how often they use pot within two hours of the workday over the last year. Supervisors are more likely to report declines in citizenship behavior and increases in counterproductive work behaviors among employees using right before and during work hours. The same negative effects are not present in workers using once their shifts end.

“The findings are obviously consequential for scholars and organizations who believe that all cannabis use negatively impacts workplace behaviors,” Bernerth explains. “Our research suggests there is no evidence that after-work usage compromises work performance as assessed by one’s direct supervisor.”

Could using marijuana actually be helpful after work?

Although the study doesn’t find any direct evidence of this, researchers contend using cannabis after work may be beneficial. Bernerth suggests marijuana’s effects could play a role in relieving job-related stress.

“The relaxation induced by cannabis may help employees restore energy spent during the day and they may subsequently return with more stamina to devote to their job once they are back on the clock,” the management professor adds.

The study also makes the case for changes in workplace drug policies. Current illegal substance tests can only detect the presence of marijuana, but not when it is consumed. This limitation, Bernerth argues, makes it hard for companies to defend a blanket no-marijuana policy.