[HKH2]

If it's spaced out well, it should be fine. It might make one feel a bit hot/irritable though.

Often caffeine tablets are sold as 200mg, so it's just two of those. (One bottle of tablets I have says don't exceed 5 pills in 24 hours - 1 gram!)

[sundvor]

Be careful with caffeine supplements such as pills and (especially) powders. Overdosing is far too easy and can be a substantial health risk, even deadly - https://www.health.com/nutrition/caffeine-powder-overdose