The prior medical literature offers little guidance as to how pain relief and side effect manifestation may vary across commonly used and commercially available cannabis product types. We used the largest dataset in the United States of real-time responses to and side effect reporting from patient-directed cannabis consumption sessions for the treatment of pain under naturalistic conditions in order to identify how cannabis affects momentary pain intensity levels and which product characteristics are the best predictors of therapeutic pain relief. Between 06/06/2016 and 10/24/2018, 2987 people used the ReleafApp to record 20,513 cannabis administration measuring cannabis’ effects on momentary pain intensity levels across five pain categories: musculoskeletal, gastrointestinal, nerve, headache-related, or non-specified pain. The average pain reduction was –3.10 points on a 0–10 visual analogue scale (SD = 2.16, d = 1.55, p < .001). Whole Cannabis flower was associated with greater pain relief than were other types of products, and higher tetrahydrocannabinol (THC) levels were the strongest predictors of analgesia and side effects prevalence across the five pain categories. In contrast, cannabidiol (CBD) levels generally were not associated with pain relief except for a negative association between CBD and relief from gastrointestinal and non-specified pain. These findings suggest benefits from patient-directed, cannabis therapy as a mid-level analgesic treatment; however, effectiveness and side effect manifestation vary with the characteristics of the product used.