No pills are effective for skin whitening.
Certain anti oxidants can give your skin a glow but don’t whiten actually. And even high doses of anti oxidants are also harmful according to few studies
Glutathione which is a skin whitening agent is not absorbed orally ( by mouth ) it’s effective only in injection form
Next Steps
Consult a dermatologist they can suggest you ways to improve your skin tone
Health Tips
Maintain healthy life style. Drink so much water and take foods which are rich in anti oxidants