Tugonon finished her Pharmacy degree with Latin honours (Cum Laude) at the University of Santo Tomas in Manila and became a Licensed Pharmacist in June 2010. Tugonon also attended the Lisa Macuja School of Ballet Manila as a ballet protégé while attending university. In 2010, Tugonon was titled Miss Pharmacy and Miss Thomasian Personality 2010 at UST
In 2011, Tugonon placed 1st Runner-up in the Binibining Pilipinas 2011 pageant. The eventual winner was Shamcey Supsup (her roommate). In 2012, Janine once again entered the pageant and won the title of Miss Universe Philippines 2012, gaining the right to represent the Philippines at the Miss Universe 2012 pageant.
On 19 December 2012, Tugonon competed in Miss Universe 2012 at the Planet Hollywood Resort and Casino in Las Vegas, United States where she finished 1st Runner-up to Olivia Culpo of the USA. Tugonon was the only Asian to place in the Top 5. Philippines placed in the Top 5 for the third consecutive year.
During the final question and answer portion of the competition Tugonon was asked a question via Twitter and read by judge Nigel Barker: "As an international ambassador, do you believe that speaking English should be a prerequisite to being Miss Universe? Why or why not?", Tugonon replied:
For me, being Miss Universe is not just about knowing how to speak a specific language – it is being able to influence and inspire other people. So whatever language you have, as long your heart is to serve and you have a strong mind to show to people, then, you can be Miss Universe.
To note, Tugonon is the second Filipino to place 1st Runner-up, after Miriam Quiambao at Miss Universe 1999.
After pageant, she graced to cover various Philippine-based magazines such as Preview, Metro, and FilJap Magazine, which eventually made it in international fashion industry. Tugonon is currently now living in the United States as she pursue her studies. At present, she is signed with MSA Models. She walked multiple fashion shows across America. Two of her biggest endorsements are Wells Fargo and Walmart. Her latest stint was on the newest commercial of Victoria's Secret Pink, the iconic fashion brand's line for college women.
In 2017, she was selected as one of the 12 finalists of NU Muses which to be featured on David Bellemere's calendar shot. Tugonon made headline in the Philippines when she walked on New York Fashion Week along with her fellow filipina models Valerie Weigmann and Stephanie Retuya.
Tugonon's relationship with Jaypee Santos was put in the spotlight. The two broke up in March 2013 after Tugonon reportedly began communicating with The Script's frontman, Danny O'Donoghue after their Manila concert that month.
Tugonon, together with Santos, appeared in ABS-CBN's "KrisTV" in April 2013 where she admitted to being a huge fan of The Script as well as her break up with Santos due to her communication with O'Donoghue, after host Kris Aquino publicly embarrassed Santos in front of the camera. However, Tugonon stated that he did not have a relationship with the singer and that the break up was only for the purpose of "thinking things over". Nevertheless, Tugonon received a lot of criticisms from netizens over her actions towards Santos on national television.