Lip injections for a small mouth? (Photo)

Thank you for your question. I suggest that you consult with your board certified facial plastic surgeon because an in-person consultation is necessary to examine your face and tell you if the procedure can achieve your desired result. There are natural lip injections through fat injections.
Best wishes,

Lip augmentations with fillers would be a great option to improve the fullness, suppleness and symmetry of the lips. I prefer to use a micro cannula to inject the lips to prevent bruising. Cost will vary and can be discussed at your consultation. 
I hope this helps.

Thank you for your question. From your photos, you appear to be a great candidate for lip augmentation with hyaluronic acid fillers, such as Restylane or Juvederm. Fillers are a great non-permanent way to help improve the fullness, suppleness, and symmetry of the lips and typically results last 6-12 months. I do not advise having more than 1 syringe injected at a time as to avoid overcorrecting. You can always add more filler later if needed. I recommend having a consultation with an expert injector to determine the best treatment plan for you. Best of Luck!