Will Changing to a Different Pill Help my Melasma?

Lower dosage birth control pills may slow the progression of melasma, but are unlikely to stop or reverse the pigmentation.  Often, I recommend that patients switch to a non hormonal IUD.

Hello MissP.  It's worth a try, but the bottom line is that no one knows until you change it.  Melasma is a very difficult condition to manage and from what we see in our practice, once you have it, it's very difficult to modify.  We have found that high dose hydroquinone is the only way to manage the condition (includes 3 month "rest periods") and we have tried many different treatments.

We have not seen a patient indicate that they experienced an improvement of their condition when changing birth control.  Sorry about that.

Melasma is discoloration of the upper cheeks, upper lip, or forehead, most commonly seen in women of childbearing age.  It tends to develop during pregnancy (hence its nickname "the mask of pregnancy") or while taking a birth control pill.  Regardless, its onset is triggered by the combination of estrogen and sun exposure.  No sun - no melasma.
Melasma is like a light switch, except one it is turned on, it can't be turned off... Stopping birth control pills will not make the melasma resolve completely.  After all, you still make estrogen...
That does not mean melasma can't be treated successfully.  The key is to avoid sun exposure strictly: avoid the sun in peak hours, use a broad-spectrum, high SPF (50+) sunscreen, applied liberally, and reapplied often, and wear a hat with a good brim.  Studies show that this alone is the main factor in reducing the darkness of melasma.  
You can also see a dermatologist to discuss treatments such as hydroquinone, which blocks the key enzyme that makes melanin, the brown pigment in the skin.
Avoid treatments such as peels and laser - these may provide temporary benefit, but the melasma will always come back.  In addition, those treatments may in themselves cause change in your skin color (post-inflammatory hyperpigmentation).