1. Creatine 

So this is a common conclusion; there is a mountain of evidence supporting creatine's effects on muscle gain. Creatine is a naturally occurring full source in the body that aids in the production of quick, explosive energy. As a result, we can train harder and gain strength. I personally use reactive supplements pure creatine monohydrate, but any powder from a reparable brand is fine; just make sure it's Creapure as this is higher quality. Also, the loading phase is optional if you don't want to do it because creatine is like gas in your car; once you're full, it's excreted, so whether you fill up quickly or slowly, you'll still be full. On workout days, I take 5-6g, with 3g before and 3g after. 

2. Protein Powder 

Now Before I go any further, I'd like to point out that protein powder is not a miracle supplement; it won't help you gain muscle unless you eat a well-balanced diet, and it's only really necessary if you can't meet your daily protein requirements from whole foods like chicken breasts. Protein, on the other hand, is required to build muscle mass because it repairs and rebuilds the muscle fibres that we break down during workouts. I recommend 1g of protein per pound of body weight for most people, and 1.5g per pound if you train 6-7 times per week. My protein powder picks include USANA's Nutrimeal, Reactive Supplements all natural whey isolate, and Nuzest's Clean Lean Pea Protein (cappuccino flavour). 

3. Greens Powder 

Greens powder is also great for muscle mass building, especially if you struggle to get all of your veggies in for the day. It is fantastic to use it first thing in the morning, 15 minutes before your first meal, and in your post-workout shake because it helps to alkaline the body, which is necessary for muscle building because the body cannot build muscle in acidic conditions. Living fuels super greens (tastes great) is my personal favourite; Good Green Vitality by Nuzest is another good one.