Melasma is a tricky condition to treat as there are many factors involved and the pigment can be situated superficially, deep in the skin or a combination of both superficial and deep.
However, there are treatments available to treat this condition via different pathways.
Personally, I use topical lightening creams, orals and different machine-driven therapies to target the pigment at different levels in the skin to get optimal results. Treatment of melasma is like a regime and requires patience as multiple sessions are required.
Nonetheless, you should also have an examination done as not all pigmentation are melasma and different types of pigment will require different treatment modalities. Hope that helps.
All the best!