How do I lighten my bikini line? (Photo)

HQ products as well as cosmelan are great starting points for evening out skin tone and lightening. These can safely be used down under. Moreover, laser treatments may help as well. See an expert in order to review your case. Best, Dr. Emer. 

There are many reasons why the skin darkens which may include sun exposure, inflammation, existing skin conditions, medication, genetics, friction, etc. There are many ways to lighten the skin including lasers and peels. IV therapy may also be helpful for you. It involves directly injecting a concoction of vitamins and minerals into your bloodstream. The concoction will be tailored by the doctor depending on your needs which for this case is skin lightening.

Thank you for your question and posting pictures.  We have been very successful lightening the pigment in personal areas including areolas, bikini area, knees & elbows using the PicoSure laser with the FOCUS and / or Flat Lenses with a series of treatments.  FOCUS lens treatments have the extra benefit of reducing any texture issues.  PicoSure has almost no downtime.  This is one of our go to treatments for patients older than 40 and worried about the signs of aging.  This laser is safe for all skin types.  
We also send some hyperpigmentation patients home with prescription strength 4% Hydroquinone (HQ).  Do not buy it over the counter or off the internet.  Laws vary by state.  In Texas, physicians can prescribe and dispense in office.  Start with sunscreen every day!  Once you have treated your hyperpigmentation to your satisfaction, you will probably need a follow treatment every 6 to 12 months depending your level of re-pigmentation.  Best of luck