Objective: To evaluate the opinions of medical cannabis (MC) users on the effects of Cannabis indica vs. those of Cannabis sativa on conditions and symptoms through an online survey.

Design: Survey of 95 non-randomly assigned MC users. A two-sided chi-square test followed by Bonferroni post hoc multiple comparison and Fisher exact test were used to determine correlations. The Cronbach α was used to determine internal consistency.

Setting: Announcements on 13 MC websites with links to SurveyMonkey.com.

Participants: Self-identified MC users.

Intervention: Web survey.

Outcome measures: Species effects were compared regarding health symptoms, conditions, purpose, route, and trust in product label.

Results: Trust in the purity, the route of administration, or the purpose (recreational vs. medicinal) did not differ between the two species. A preference for C. indica was statistically significant for pain management ( p=0.001), helping with sedation ( p=0.015), and sleep ( p<0.001). C. sativa was preferred for euphoria ( p<0.001) and enhancing energy ( p=0.022). The conditions reaching statistical significance for C. indica preference were: nonmigraine headaches ( p=0.042), glaucoma ( p=0.036), neuropathy ( p=0.024), spasticity ( p=0.048), seizures ( p=0.031), insomnia ( p<0.001), and joint pain ( p=0.048). For C. sativa, no conditions reached significance. The MC websites' descriptions of effects that agreed with the survey results are listed. Some conditions had very few respondents. The internal consistency/reliability (Cronbach α) was adequate for the condition scale but not for the symptom survey.

Conclusion: In this anonymous Web survey, which had limitations, the two species had different effect associations on symptoms and conditions, possibly because of ingredient differences. Future surveys and subsequent prospective definitive trials are needed to confirm the findings.