The first Super Saiyan transformation occurs when a Saiyan who has reached his natural limit is overcome with uncontrollable emotion; in most instances, rage.
The first Saiyan seen to achieve Super Saiyan in the series was Son Goku when fighting Freeza.
A Super Saiyan reverts to their regular state by dispersing the concentration of ki in their bodies either consciously or by force.
Only slight differences are noted from the regular Super Saiyan form, such as the muscles not receiving as much of an increase in their mass from the previous stage.
The first person to achieve this was the half-Saiyan named Gohan while battling the super android named Cell.
This form is the strongest of all saiyan forms in the manga Dragon Ball series. This form is unique compared to the other forms because of the fact that the form causes the user to rapidly consume their own energy in order to maintain the transformation; this leads to fatigue and the eventual need to revert to the Saiyan's regular state. Only Goku and Gotenks are shown to be able to utilize this transformation.
Despite the major flaws of this form, it increases speed and power far more than Super Saiyan 2.
The Super Saiyan 4 form is implied to only be accessible to pure blooded saiyans.
This form is only initially achieved when the primal urges of the Golden Oozaru are consciously suppressed. After this form is first achieved, it can be accessed afterwards without having to transform into a Golden Oozaru first. This form was first achieved by Goku when battling Baby-Vegeta, and then achieved by Vegeta during the battle with Omega Shenron. Vegeta however achieved it unnaturally by being artificially exposed to high concentrations of Bruits waves.
Beyond his regular Super Saiyan transformation, Broly's final form greatly increases his body size and muscle mass, much like the Super Saiyan 3rd Grade. However, his strength and speed exceed the limits of all variations of the regular Super Saiyan form. Additionally, his irises and pupils in his eyes seemingly disappear.
This form is also unique because it does not share the physical limits and flaws of a regular Super Saiyan, it actually counters them; gradually increasing power as fighting continues. This contrasts the regular Super Saiyan that loses power as battle is prolonged.
