Plenty of people buy Amino acids purely on the brand or because their mate said so, without knowing what truly is in the BCAA and why they are buying it. In such a flooded and competetive market, everyone is trying to beat the others with new scientifically supported formulas or added ingredients. Are these formulas new and improved or is it just a marketing spin? 
The first craze in variations is the ratio of the BCAA. When the original 2:1:1 ratio became 'old' and something new was in demand to increase sales, ratios 4:1:1 then the 8:1:1 now even 12:1:1 ratios were produced. The theory behind this was the undeniable importance of leucine and sufficient leucine within the body/diet.
However - is more actually better in this case?
There certainly is no argument from me or as far as I am aware from anyone that you want a higher dosage of leucine when compared to the iso-leucine and valine content. This has led to people assuming or believing that the higher the leucine ratio the better.
Studies have been made however which show leucine alone does not produce the same results as a a 2:1:1 BCAA product. This does not mean that a high leucine content isn't an improvement but does support the importance of the Valine and isoleucine within a BCAA product. The only ratio which has studies supporting it is 2:1:1 . This also happens to be the natrual amino ratio found within the muscle.
Why Leucine is not the only focus.
During exercise seratonin is released and this will cause fatigue or cause the body to feel fatigued, however Valine competes with the sertonin to enter the brain, so a correct or sufficient dosage of valine will lead to a reduction in fatigue.
Isoleucine has been shown to stimulate PPAR which will inhibit fat storage and increase fat burning. This is both in general and during training. However these tests have been performed on mice instead of on humans.
Now,again, this doesn't show that a higher ratio of Leucine is a negative, but it shows that it is key you have a high enough dosage of valine and isoleucine. A 2:1:1 ratio is sufficient to have enough leucine (3g) to stimulate protein synthesis, above this will just increase the cost of the product and there is the fear/theory that too much leucine could lead to a depletion in the other branch chains. When looking at the profile of a BCAA look for atleast 3 g of leucine-1g of valine and 1g of isoleucine per serving. Which to achieve this you will want a 2:1:1-4:1:1 Ratio.
The next stage of progression
Once the Ratios weren't enough to set products aside , other ingredients were added to bring further benefit. The most common of these are:
Citruline malate
Citruline malate stimulates ATP production by working against toxins/pollutants in the body, these are things such as Lactic Aid and Ammonia which all exercise causes on the body. Citraline Malate also enhances the Arginine in blood plasma, this in turn leads to enhanced NO production (pump). Cit Mal in a correct dosage is a brilliant ingredient to be included especially at the right time, this for me is Pre workout.
Beta alanine
Is a non essential amino acid. It is used and prooven in clinical studies to improve performance for strength or high intensity training and is also supported to delay muscle fatigue in adults. an effective dose of this is 3+ grams.
Beta-alanine is found in several pre workouts, you will often link this with a tingling sensation on your skin, face and ears etc. This tingling is why i would not want to sip a BCAA with Beta Alanine at a reasonable dosage in throughtout the day or at night before bed.
Electrolytes
Such as sodium and pottassium. When the levels of these in the body are sufficient they will fill the cells within the body keeping them strong and functioning. This is essential for your body, drinking too much water and not replacing these minerals can have terrible consequences and not just on performance. When you sweat you lose these minerals so having a BCAA with these in can really benefit your workout. Especially for someone who like myself during a training session will drink litres of water. Adding in some electrolytes will ensure i do not flush out all the electrolytes currently in my system.
Glutamine
This is one of my favourite things to supplement with. Any product that has it in will catch my eye but then run the risk of frustrating me by only include a tiny/trace amount so that it can appear on the tub. Glutamine has numerous benefits ranging from immune function to growth hormone production. 61% of skeletal muscle is Glutamine and it is the main nitrogen transporter within muscles. However you should aim for 10-15g atleast of Glutamine per day, so 1 serving of a BCAA with 1g of Glutamine in will not be going much for you. If there is a decent dosage of Glutamine in my BCAA i like it but i will still be supplementing Glutamine seperately.
What is the best ingredient
There is no perfect ingredient to be added, this will vary from person to person with how they respond as well as the aim of their training/exercise.
I like to sip my aminos through the day especially when dieting, which i don't want to be doing with a high dose of beta-alanine in it. However the added electrolytes do not cause an issue with this. But if my BCAA was solely for pre/intra workout I may change my selection of BCAA.
