Y Combinator's incubator classes have gotten huge.

With over 200 companies, the Winter 2019 class is by far YC's largest yet. Meanwhile, the incubator prepares to shift its headquarters from Mountain View to San Francisco.

It's so large, in fact, it's had to change the way it does Demo Day. Rather than all pitches happening on one stage, they were split across two stages (the "Pioneer" and "Mission" stages) running in parallel. So even if you were in the building, you couldn't see all the pitches in person.

Here are the 85+ startups that launched at YC's W19 Demo Day 1

By Josh Constine, Kate Clark, et al.

March 2019

Meet 23 companies that recently announced they’re part of the YC Winter 2019 batch. To see more YC W19 companies read Part 1, Part 2, Part 3 and Part 4.


YourChoice Therapeutics is developing non-hormonal contraceptives for women and men. Their first product will be a vaginal contraceptive to be applied before intercourse followed by oral contraceptives that can be taken by men and women. These products are based on blocking a protein on sperm that is required for fertilization.

Meet 23 Companies from the YC W19 Batch Part 5

By Y Combinator

March 2019

Following another highly-competitive selection round that attracted applicants from around the country, CITRIS Foundry welcomes six new startups into our program at UC Berkeley. The Spring 2018 cohort is commercializing inventions and innovations in battery production, interactivity on the web, drug discovery, human contraception, and energy grid flexibility.

Six new startups join CITRIS Foundry

By Julie Sammons

March 2018

The options available to women who want to avoid getting pregnant today are bad. Most, like the widely used birth control pill, feed man-made estrogen and progestin hormones to women, which are capable of causing a number of awful side effects.

YourChoice Therapeutics — a startup launched by a team of Berkeley researchers, including two experts in sperm physiology and sperm-egg interactions — dreams of producing a unisex, non-hormonal alternative to existing contraceptives. The company has raised $400,000 in funding to date, plus a $150,000 check from Y Combinator. YourChoice will make its big pitch at Y Combinator Demo Days next week.

YourChoice Therapeutics is developing unisex, non-hormonal birth control

By Kate Clark

March 2019

On its quest to fertilize the egg, a human sperm cell confronts resistance left and right. It must overcome uterine immune defenses and navigate a maze of folds in the fallopian tube. As it reaches its goal, it encounters the thick, multi-layered egg-protective shield – the zona pellucida. There, its tail must shift into hyperdrive to power the sperm cell through the egg’s last barrier.

Beyond Hormonal Birth Control

By Wallace Ravven

February 2019