The FDA notes the most severe adverse events include melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome, and prolonged and painful boners
In addition to the requirements on audits and record retention at 512.135, we proposed at 512.770(c)(1) through (4) that ASM participants who wish to offer ASM beneficiary incentives must also ensure documentation of the incentives distributed according to the following requirements: ASM participants must maintain documentation of items and services furnished as beneficiary incentives that exceed $75 in retail value
Side effects to Vitamin B12 are SO rare that they cannot be estimated from current data (in other words, less than 1 in 10'000)
Storage, Handling, and Travel Store Vitamin B12 Injection according to the package label
If you encounter: Dizziness: Try to rest and avoid sudden movements after administering ME 12 INJECTION 1ML
"Antiepileptic drugs interact with folate and vitamin B12 serum levels" (PDF)