Systemic Insecticides

Are they safe to use on weed plants? I'm still early in veg and have at least 2 weeks of veg plus all of flower left. I usually flush before flower, at 1 month, then before harvest.

Will I be alight or is it better to avoid them?

It depends how long it will be before you initiate flowering and how long it takes for the pesticide to leave the plant. I definitely would use a systemic pesticide to preserve my mother plants but I would want all new plant growth to use to clone with. Even using all new plant growth I would follow the manufacturers recommendations plants meant for consumption. Both items must be true for me to want to flower that plant, new plant growth will be used and it will be outside of the safe time listed by the manufacturer.

Only in veg. Never in flower, theres not enough time left for it to be out of its system.