Fischer et al. 1 have now translated the 2017 Lower-Risk Cannabis Use Guideline (LRCUG) to Brazilian Portuguese. The LRCUG includes ''a set of 10 recommendations on how cannabis users may most effectively reduce the risks for associated health harms,'' being aimed at those who are already using cannabis. I offer the following comments on the recommendations:Recommendation 1 -No comment. Recommendation 2 -''y most clearly that which begins before age 16 yearsy is associated with multiple subsequent adverse health and social effectsy'' -Cannabis interferes with the 'pruning' of synapses, myelination, and other milestones in the development and maturation of the nervous system since conception, and it does not stop at age 16. This recommendation could help prevention efforts by stating: ''y initiation, if inevitable, should be delayed until full adulthood (age 22-25 years).'' Recommendation 3 -''y it is advisable to use cannabis containing high CBD:THC ratios'' -High doses of CBD may lead to dissociative states. 2 A safer recommendation might be: ''Do not use cannabis. If you cannot abstain, avoid preparations rich in THC and low in CBD.'' Recommendation 4 -The authors consider the available evidence limited. Synthetic cannabinoids are full agonists of cannabinoid receptors, are more potent than THC, are clearly associated with psychotic states, and may be more neurotoxic than phyto-cannabinoids. 3 Recommendation 5 -''it isy preferable to avoid routes of administration that involve smoking combusted cannabis material (e.g., by using vaporizers or edibles)'' -Vaping is increasingly used in North America, including by minors, which involves the possibility of inhaling high THC concentrations from cannabis oil, wax, or liquid preparations. 4 Recommendation 6 -''y avoid practices such as 'deep inhalation' breath-holding, or the Valsalva maneuvery as these practices disproportionately increase the intake of toxic material into the pulmonary system.'' -This recommendation could mention the higher blood and brain levels of THC and other cannabinoid substances, with their own toxic effects from these maneuvers.Recommendation 7 -''y keep cannabis use occasional (e.g., use only on 1 day/week, weekend use only, etc.) at most.'' -In a cohort of 50,000 Swedish Army conscripts, it was found that using cannabis 50 times