If you're currently supplementing with Citrulline Malate, you could do what I do, depending on when you take your BCAAs.
Simply dissolve your CM completely into your water or crystal light or whatever you take your BCAAs with, then add your BCAAs, stir, wait a few minutes, and voila!
As has been mentioned, the BCAAs, especially the leucine, are hydrophobic. Of course that's very relative, but what's certain is that a lower pH (and a higher one, incidentally) in your solution will significantly increase the rate at which BCAAs dissolve.
I've heard people recommend things like orange juice and lemon and even cola, but nobody seems to recall that CM is the sourest mother f*ckin' supplement on the planet
The malic acid from the CM will outshine your orange juice and lemon when it comes to dissolving BCAAs, and it's a damn useful supplement in its own right! Plus, the CM will make your drink so effin' sour you'll hardly notice the bitter taste of the BCAAs at all--a win/win!
Room temperature water works best, and shaking or blending is better than stirring, but I've stirred the above-mentioned combo into ice cold water and it still works like a charm.
A lot of people take their BCAAs post-workout to get the myriad benefits including some that you really only want /after/ your workout like increased insulin response with carbs. Likewise, many people only take CM pre-workout, and might not think to combine the two.
I personally use BCAAs both before and after, as they are readily consumed by the muscles themselves and used for fuel, helping with endurance /during/ my workout, while staving off any potential muscle catabolism that might occur from BCAAs being used preferentially for fuel. This way, I can always mix my CM with my BCAAs, as I take both pre and post WO.
For the record, I use 6g a day of CM split into two doses, with 20g of BCAA split into either 2 or 3 doses depending on my schedule.
For anyone else out there looking for a solution to BCAA solubility, I urge you to try this. Works better than anything else I've tried, and you can still mix in whatever other supps you like without it getting nasty like it would if you used orange juice or cola (yuck).
Hope this helps!
