The short answer is Until you are satisfied with improvements in communication and the treatment no longer seems to be helping. Another useful response is, Consider discontinuing mB12 when stimming becomes more disruptive than language acquisition. I find it peculiar that parents pose this question at all
Document the timing and intent clearly
well-tolerated in mice, rats, rabbits, and dogs with no serious organ toxicity.[34][35] Clinical Safety : Mild local irritation possible at injection sites, but no systemic adverse effects reported in trials.[36][37] Potential Risks : Theoretical concerns include pro-angiogenic effects potentially promoting tumor growth, though no evidence supports this in studies.[38] Long-term human data is limited, so monitoring is advised
You might conclude that a certain protocol is ineffective when, in reality, the compound you were using was no longer active
"Norvasc product information"
The process requires patience because it is gradual rather than instant