> I am sure you don't have the equipment to measure an appropriate dose of caffeine (because scales accurate to 100 milligrams are not very cheap for household use...)

The powder can be used by volume; it's not hard to be precise down to a quarter teaspoon or less...

> it is not safe to 'eyeball' it.

Huh? It's perfectly safe to eyeball it if you are not utterly incompetent at sizing up volume; it's a fairly bulky powder and I divided mine up over 3000 pills so I know each pill has less than 130mg. You can find studies that use up to a gram. The LD50 for my bodymass is somewhere upwards of 43 grams, as opposed to the 200mg or so that I use. As a heavy tea drinker, I have plenty of tolerance (http://www.caffeinedependence.org/caffeine_dependence.html indicates at 40mg per 6oz, and each mug around 12oz, I'm easily getting 2-300mg a day).

> You will start to notice unpleasant effects (restlessness, etc) around 200-500mg, and then above that (say 600-1000mg) you may start to get into what could be called toxic effects (palpitations/arrhythmias, GI bleeding, potential for seizures)

Where are these figures coming from, and why on earth are you presenting them without qualification as if they apply to either me or the comment I was replying to? I'm guessing from how these are lowball numbers that they are meant, if at all, for people who do not consume caffeine regularly or at all. I've used ~600mg to see what happens, and I didn't see your toxic effects as one would expect from tolerance; even 300mg doesn't cause the slightest shaking if combined with l-theanine.

And even if I had noticed such negative effects, it wouldn't bother me because I would have to error by 3x the usual amount of powder. A quarter-teaspoon doesn't even hold that much in the first place!

> Caffeine has a half life of 5-8 hours and so by the time you go for your next dose you probably haven't cleared the first one, so you can definitely build up serum concentration.

I am well-aware of this, and don't use any after 5 PM or so; with a Zeo sleep tracker it's easy for me to see the effect of night caffeine use. (I can't speak to whether the original commenter is also responsible. But this is an aspect of caffeine that is not a problem with half-sensible use.)

> Your body can develop a dependency on caffeine and you'll get splitting headaches when you aren't taking it.

As with every other one of your claims, one's mileage will vary... Every few weeks I do quit all substances. I get a mild headache for a day, and that's about it. I think the guy I was replying to (a regular user of caffeine pills, remember?) also knows how withdrawal affects him and whether it is a problem or not.

> It is not easy to die from caffeine toxicity, but it is definitely possible when you have powder on hand.

I also have enough water on hand to kill myself.

> the stuff is BITTER. Really, really unpalatable.

It's not nearly as bad as some other things like piracetam. Not that it matters at all.

> Tablets, capsules, etc. are formulated with binders, preservatives, and inert ingredients that often take up much, much more space than the active compound.

Hence the earlier point about powders coming with a volume->dose specification which makes measuring much easier.

> I'm a pharmacist

Ah, so that explains the well-intentioned - yet over-generalized and somewhat alarmist - advice.

While we're at it, I'd point out that caffeine comes with a whole laundry list of long-term effects - both positive and negative: http://en.wikipedia.org/wiki/Health_effects_of_caffeine#Over... Given the ambiguity, it's not worth worrying about long-term effects unless you are highly risk-averse.