There are no non-surgical, ‘natural’ remedies that are effective for breast enlargement.
Generally speaking, dietary supplements, medication, and topical applications will not be able to reliably enlarge the breasts. The most predictable and effective method of achieving larger breasts is augmentation with implants.
Although this is a surgical procedure, it is relatively straightforward, with a very predictable outcome and low complication rate. An alternative to breast augmentation with implants would be fat grafting.
This has the advantage of using the patient’s own fat. However, less enlargement can be achieved compared to implants and sometimes multiple procedures are required.