10 mL, depending on personal preference, is best injected as three injections injections of 3.3 mL (many 3 mL syringes can be loaded to 3.3 mL approximately), 4 injections of 2.5 mL, or 10 injections of 1 mL. Those who like getting the effect where the oil from the injection increases the size of small bodyparts e.g. biceps a little, might prefer the 10 small injections, whereas those preferring to save time would prefer the fewer injections. Personally, I find Schering Primo to be somewhat painful on injection, giving a dull sort of ache though only moderately, so I don’t prefer it for the biceps.
Usually the reason someone wants to do Primo/Winstrol is precisely because they want to use a stack which doesn’t require other drugs to counter side-effects, and which is itself mild in terms of side effects. So in a sense, asking if Dianabol or testosterone propionate would go well with the stack is like asking if a Double Whopper with Cheese would go well with your grilled flounder, baby peas, and vintage white wine.