Brief Answer:
Need photograph

Detailed Answer:
Hello XXXXXXX
Welcome to healthcare magic.
I can think of a few possibilities. It could be pigmented contact dermatitis to bleach, lichen planus , post inflammatory pigmentation due to rash caused by bleach or fixed drug eruption.
Do you smoke ? Smoking can cause lips to become dark.

Do you have any skin rash elsewhere on the body ?
Do you have burning sensation and erosions inside mouth ?
These can be seen in lichen planus.

After taking a medicine did you develop any itchy rash over lips before this darkness started ? That is how fixed drug eruption develops.

You have a feature to upload the images by yourself at the right side of the query page, please utilize that so that I can answer your query better. You can also send the image as attachment to YYYY@YYYY , with the subject as 'Attn: Dr. Johny Chacko'.

Waiting to see the photograph.
Take care

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Brief Answer:
Lightening gel at night & sunscreen in the morning

Detailed Answer:
Hello,
Welcome back.

Thanks for uploading the picture.

In my opinion it looks like post inflammatory pigmentation due to the bleach that you applied.
I usually treat such cases with a lightening gel like kojivit gel to be applied at night over the lips. According to the improvement I take a call whether to continue kojivit or not at the end of one month and as it is a non steroidal gel it is safe for long term use.
Sun protection is a very important part of treatment and I usually recommend a lip balm with a sun protection factor like Biotique's Bio morning nectar or Body shop's Vit E lip care to be applied in the morning before going out and re-apply every 4 hours.
Hope I have answered your query. If you do not have any clarifications, you can close the discussion and rate the answer. Wish you good health.

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Brief Answer:
Kojivit from pharmacist

Detailed Answer:
Hello XXXXXXX
kojivit gel is available only in medical shops. Lip balm is available in cosmetic stores.
Hope this helped
Take care

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