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How quickly does Supprelin LA work?

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 30, 2023.

Official answer


Supprelin LA starts to work within 4 weeks of implantation and by that time you should see signs that your child’s puberty is stopping. Do not be alarmed if during the first week of Supprelin LA treatment you an increase in signs of puberty in your child, such as light vaginal bleeding or breast enlargement in girls. This is to be expected because initially, Supprelin LA causes an increase in some hormones, but after 1 week, hormone levels decrease and puberty starts to abate.

Research has shown that suppression of luteinizing hormone (LH) was induced in all children with central precocious puberty (CPP) 4 weeks after implantation and continued through to month 12. Other outcomes, such as levels of estrogen and testosterone, bone age advancement, linear growth, and clinical progression of puberty all decreased, indicating stabilization of disease. By month 9, 100% of females showed estradiol suppression which decreased slightly to 97% by month 12. Testosterone suppression was reported in 100% of males at month 12.

How does Supprelin LA work?

Supprelin LA works by stimulating GnRH receptors so much that it desensitizes the receptor and down-regulates the secretion of LH and FSH and subsequently estrogen and/or testosterone. Because it works in this way, infusions of Supprelin initially produce a transient increase in hormone levels, which may be seen as an increase in the signs of puberty, but continued stimulation results in a profound decrease in hormone levels. Supprelin LA belongs to the class of medicines known as GNRH agonists.

What is Supprelin LA?

Supprelin LA is a small flexible implant, 1.3 inches (3.5cm) long that is implanted just under the skin of the upper arm and designed to continuously release histrelin acetate, a hormone that helps stop the production of estrogen, testosterone, and other sex hormones. Supprelin LA may be used to treat children with central precocious puberty (CPP). One full year of medication is contained in one implant

The entire procedure can be done in a doctor’s office using a local anesthetic.

  • Supprelin LA (histrelin acetate) Updated 12/2019 Endo Pharmaceuticals Inc.
  • What to expect with SUPPRELIN® LA

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