Brief Answer:
Detailed answer below.

Detailed Answer:
Hi Jessikajgreen24,
Thank you for the query. I have read it &understand your concern.
Dark lower lip could be due to following causes.
- It can be genetic.. lip colour running in family.
This condition can not be changed nor needs treatment. ... wise selection of branded lip cosmetics when you are socialising (with expert advise if needful)can be the answer.
-lip colour depends on the colour of bloodflowing under lip skin.. so both less or more haemoglobin in blood can cause it....This can be known/excluded by simple blood test..followed by needful treatment by your family physician.
-Excessive melanin formation in skin can be the cause.. This may be seen with- excessive exposure to sun/ drinking alcohol with illicit substances ,home made brues where acidic substances are are added to hasten the fermentation/Betal leaf or areca nut chewing
The cause if any one of above, needs to be noted&excluded from use...along with normal lip care after expert cosmetologist's advise.
- Dry lips from any cause... weakness,less water intake,exposure to heat or Sun or smoking(not applied if no smokingat all) can lead to dry lips which get chopped,over licked ,infected... to cause
darkening.
Use of expired or low grade lip cosmetics can cause allergy or damage to skin
Hormonal imbalance can lead to hyper pigmentation(Thyroid problems).
All these cause to be scrutinised investigated&treated cause specifically with a guidance of expert physician.
- Use of certain medicines like broad spectrum antibiotics ,anti depressants ,preventive medicine for maleria can cause it. please be in touch with your physician with list of medications under use... &get the point solved.
- Use of home remedies with handling &scrubbing of lips can lead to damage to the delicate skin of lips &cause harm.
I hope that helps you. Any follow up query is welcome.
Thanks.

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