BBL for small frame? I'm 5'3 and125 lbs, but it's so difficult to put on weight

You do not need to gain weight to get an excellent result if you select the right surgeon.
Kenneth Hughes, MD

Thanks for your question. Without any photos, its hard to make an assessment just based on your weight whether or not you would be a good candidate for BBL.  During this procedure, fat is harvested via liposuction from different areas of the body such as waist, back, flanks and thighs and then transferred to the buttocks. I recommend an in-person consultation with a board certified plastic surgeon who can evaluate how much fat can be removed and transfered to your buttocks at your current size. They will then be able to give you a better idea of what the expected results would be.

Hello dear!!
Thanks for the question.
I would recommend you to post pictures to give you the best recommendation possible. If you are healthy it is possible to perform the procedure.
 I recommend to book a consultation with a board certified plastic surgeon in your area to discuss the best options for your goals. 
Good luck :)

Thanks for the question.  Photos would aid in evaluating if you have enough fat stores to augment your buttocks.  Multiple areas may be liposuctioned to obtain more fat.  An in office consultation would answer all of your questions.Best wishes.Dr T

Although you are 5'3" and 125 lbs, you may still be a candidate for buttock augmentation with fat transfer. There are many donor sites which need to be considered and how much of a buttock you have are also important considerations. You need to consult with a Board Certified PS with extensive experience performing buttock augmentation. 

If you do not have enough fat reserves then a BBL might not be the right procedure for you.  Buttock augmentation with implants might be better.

It is difficult to evaluate your candidacy with no photos posted. I would recommend a consultation with a plastic surgeon who performs many of these procedures, has great reviews and photos, and is an expert in this field.

Thank you for your question. Can you please add a few photos to your question so that we can inform you better,best of luck 

Hello.Thank you for your question,It is necessary to evaluate your photographs to give you the best option and what is the best procedure to achieve your goal.Regards.Dr. Kemil Issa,  Certified Plastic Surgeon

Hello,Thank you for sharing the information, it is a pleasure for me to answer your question.
It is difficult to assess the type of procedure you need without seeing your photos.So it is advisable to consult with a certified plastic surgeon, for a good evaluation, to provide you with all the information you need to know about the appropriate recommendations, so that you can achieve the desired goals in your body.
I hope this answer will help you,My best wishes for you...