Best for what? for a healthy liver? for skin whitening? The latter is just a side effect.
uu, side effect ng sythetic glutathione..
in reality, from the moment we're born, abundant na ang katawan natin ng glutathione. it's starts to decrease at the age of 20 at about 10-15% per decade (or 1-2% a year) depending sa lifestyle.
if whitening nga, eh di sana maputi na lahat ng tao the moment pinanganak ito. wala na rin sanang mga negro ngayon lols..