Alyson Hannigan Lost 20 Lbs. on Dancing with the Stars

Alyson Hannigan is opening up about her mental and physical health following her time on Dancing with the Stars.

On Saturday, the actress, who made it to the ABC show’s finale last Tuesday with dance partner Sasha Farber, shared an emotional Instagram post about her experience — and revealed that she experienced a 20-pound weight loss during production.

Alongside a side-by-side of a pre-season promo pic and a photo from the DWTS finale, Hannigan, 49, wrote, “The before and after says it all. I lost 20 pounds of both weight and emotional baggage during my time on @dancingwiththestars.”

The Buffy the Vampire Slayer actress also expressed gratitude to Farber, writing, “I can’t thank @sashafarber1 enough for helping me shed my insecurities and getting me to the confident and strong place I am today!”

In the comments, Hannigan was congratulated by her DWTS costars, including Harry Jowsey, Val Chmerkovskiy and Farber — who also celebrated her with a post of his own.

Alongside the same split of Hannigan, the pro dancer wrote, “I wanted to post this picture and celebrate how proud and hardworking my partner was during the season!!!!”

“I believe dance is the best way to exercise, stimulate the brain and have fun in the process,” Farber added. “I call it ‘BodyBySasha’ who wants to sign up!!!!!”

Hannigan gave her stamp of approval in the comments writing, “Take it from me, it WORKS!!!”

On Friday, the How I Met Your Mother star shared a longer post congratulating DWTS season 32 champions Chmerkovskiy, 37, and Xochitl Gomez — and commemorating her time on the series.

Alongside a compilation of behind-the-scenes videos from the season, Hannigan wrote, “Where do I even begin? I really don’t have enough words in my vocabulary to express my gratitude for this experience. To go into this journey with mostly fear, and come out how I feel now is indescribable.”

“I cannot thank @sashafarber1 enough for everything he gave me, shared with me and experienced with me,” she wrote. “I couldn’t have asked for a better partner. Thank you for not giving up on me. Thank you for giving me confidence and making me feel like I could do this and then getting me there and having so much fun along the way. I am so glad that you came into my life and you’re not gonna get rid of me now.”

Hannigan continued, “To all the other pros and cast, thank you for being a part of this journey. I enjoyed getting to know you and you’ll always have a special place in my heart. To the incredible crew this is a massive show and everyone is doing the most amazing job. Wardrobe department. Your skills are beyond anything I’ve witnessed. Thank you for always making me look and feel my very best. Can I work in your department now?”

“And to everyone who supported me and voted for us thank you from the bottom of my heart,” she added. “It means the world that you allowed me the time to improve and stay on the show. And a huge congratulations to @_xochitl.gomez and @valentin you guys are amazing!!!”

Gomez, 17, penned a sweet response in the comments, writing, “It was a treat to see you almost every day. I’ve got a hole in my heart where your smile filled my day.”

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Ahead of Hannigan’s finale appearance — along with winner Gomez, runner-up Jason Mraz, and fellow finalists Ariana Madix and Charity Lawson — the actress revealed to PEOPLE she thought she had been announced as a finalist by accident.

“I thought [host Alfonso Ribeiro] made a mistake,” Hannigan told PEOPLE at the semifinals.

“I thought he meant to say Ariana and he said my name first and I just was waiting for him to correct himself and then I couldn’t believe it,” she said. “I was totally shocked.”