Relaxin is a polypeptide hormone released by the corpus luteum (ovary), uterus, placenta and mammary gland. It plays an important role in pregnancy and childbirth, but there's still much mystery around the function of this multi-tasking hormone. Some of what we do know is that relaxin prevents uterine contractions early in pregnancy to avoid premature childbirth. During childbirth, it helps the cervix dilate and the vagina to soften and widen. In blood circulation, levels of relaxin rise after ovulation and lower again if pregnancy does not occur.  

Relaxin has also been discovered in men, although its function is even more unclear in men. Secreted by the prostate, it is found in semen. It is thought to assist the movement of sperm cells in the semen.

Recent findings show that relaxin also decreases tissue fibrosis in the heart, lungs, kidney and liver. It supports the growth of new blood vessels, helps heal wounds and is anti-inflammatory. Even though researchers are still figuring out what exactly it does, relaxin seems to be a pivotal hormone in various systems of the body, aside from just reproductive. Cool!

“We have received the organs and it was like Christmas morning for the transplant team.” - Children’s Hospital of Philadelphia

Maybe not transplantable organs, but we hope The Guts bring lots of joy to the kids awaiting organ donations this holiday season!

I'm a Liver Not a Fighter MugAbout 90% of the human body is water, yet 1 in 10 humans don’t have access to clean H2O. This week we are donating profits from iheartguts.threadless.com to Charity:Water to help increase access to 💦  clean water 💦  to those in need all over the world. Buy stuff like this I’m Liver Not a Fighter mug and help others 11/28-12/5, our Giving Tuesday lasts all week! Buy more than $45 US/$80 international and we'll throw in free shipping with coupon code CHEER5f0d57, too! #givingtuesday
Happy Organ Erasers by I Heart GutsBring your guts back to school with our happy organ erasers! Get rid of mistakes or play with them as a team, these gutsy erasers are sure to bring a smile to your face. Easy way to collect all your major organs! When I was an eraser-obsessed fourth grader, I had a severed finger eraser that was my absolute favorite thing in life. Bringing these erasers to life is truly a dream come true, and we hope you'll like them, too!