@miched.. Studies show that HQ 4 percent works well with a 10 percent glycolic acid cream or Retin a.. Consider adding these to your routine to see a difference...
You'll need at least four to six weeks to start seeing noticeable results. Your results will also be more significant and appear a little faster if you practice good habits.
Everyone else has already said exfoliation, which is vital in skin lightening (all that dead skin in the way dulls your complexion and prevents your product from penetrating well). You said you only use it at night, so I recommend gently exfoliating your face and neck once per night before you apply your product. There's no need to exfoliate more than once per day, as that can over-irritate and even thin out your skin. Wear zinc oxide foundation, maybe a hat, whenever you're out in the sun to prevent re-darkening (you'll need to maintain this habit even after you stop using the product).
You should also use a vitamin C serum! Vitamin C is a great multipurpose agent that gently exfoliates, encourages collagen production, protects from UV rays and gives your skin a bright, healthy glow. It'll definitely bolster your results. I make a DIY vitamin C serum at home and it's one of my favorite products.
Likas Papaya Soap is that really needed? also dose it work okay on senstive skin