Sarah Michelle Gellar is remembering a friendship of a lifetime. 

Two days after Shannen Doherty died at the age of 53 following a long cancer battle, the Buffy the Vampire Slayer alum remembered her close friend with an emotional tribute.  

“How do you possibly find the right words to sum up 30 years of friendship?” Gellar wrote alongside several personality photos of the pair July 15 on Instagram. “I keep reminding myself it only hurts this much because, there was so much love. Thank you, for all your kind words and support. I love all the messages about how @theshando was important to you. So let’s honor her.”

Gellar noted that the Charmed star loved animals and specifically dogs—Doherty owned a German Shepherd named Bowie—more than anything, and encouraged her followers to support local charities in her friend’s memory. 

“Whether that’s donating money, stopping by your local shelter and just offering cuddles and walks to animals housed there or even just tagging them in the comments so other people can learn about their work,” Gellar continued. “I know that would make our girl happy (and illicit [sic] that deep throaty laugh we all loved).”

The 47-year-old shared more photos throughout the duo’s three decades of friendship to her Instagram Stories. Moments included a snap of the pair in front of New York’s Metropolitan Museum of Art and basking in the heat on an inflatable bull pool lounger. Gellar even shared snaps from the pair’s WB days in the ‘90s, proving just how long their bond has lasted. 

And Gellar’s post was only the latest tribute to Doherty following her July 13 death. Her Beverly Hills, 90210 costars, including Brian Austin Green, Jason Priestley and Jennie Garth, the latter of whom reflected on their deep friendship, also shared tributes.

“I am still processing my tremendous grief over the loss of my long time friend Shannen the woman I have often described as one of the strongest people I have ever known,” Garth wrote to Instagram July 14. “Our connection was real and honest. We were so often pitted against each other but none of that reflected the truth of our real relationship which was one built on mutual respect and admiration.”

Keep reading to see all of Doherty’s loved ones pay homage to the late icon.

“How do you possibly find the right words to sum up 30 years of friendship?” the Buffy the Vampire Slayer wrote on Instagram July 15. “I keep reminding myself it only hurts this much because, there was so much love. Thank you, for all your kind words and support. I love all the messages about how @theshando was important to you. So let’s honor her.”

"I am still processing my tremendous grief over the loss of my long time friend Shannen, the woman I have often described as one of the strongest people I have ever known," the actress, who played Kelly Taylor, frenemy of Shannen's Brenda Walsh, on 90210, wrote on Instagram. "Our connection was real and honest. We were so often pitted against each other but none of that reflected the truth of our real relationship which was one built on mutual respect and admiration."

Shannen, she said, "was courageous, passionate, determined and very loving and generous."

"I will miss her and will always honor her deeply in my heart and in my memories," Jennie continued. "My heart breaks for her family and Bowie [Shannen's dog] and all the people who loved her.

"I don't have outwards words yet.," Tori wrote on her Instagram Stories, alongside a selfie of herself and Shannen and several broken heart emojis, "but WE knew and that's what matters."

“Shocked and saddened to hear about the passing of my friend Shannen,” the actor, who played Brandon Walsh, the twin brother of the actress' character Brenda Walsh on Beverly Hills, 90210, expressed on Instagram. “She was a force of nature and I will miss her. Sending love and light to her family in this dark time.”

"Shan. My sister," the Beverly Hills, 90210 alum wrote on his Instagram Stories. "You loved me through everything. You were a big part of my understanding of love. I'll miss you more than I know how to process right now. Thank you for the gift of you."

“So young – so sad,” the Beverly Hills, 90210 and former SAG-AFTRA president wrote on Instagram. “May you RIP Shannon. I know Luke is there with open arms to love you."

The actress-turned-therapist, who played Cindy Walsh, the mother of Shannen and Jason Priestley's twin characters Brenda and Brandon, wrote on Instagram she was "shocked and saddened" by news of her onscreen daughter's death.

"What a journey she has been on!" she wrote. "Gone too soon. Throughout, she stayed true to herself and gave us an example of courage and perseverance in facing her own death. May she rest in peace."

"It's no secret that Shannen and I had a complicated relationship, but at its core was someone I deeply respected and was in awe of," she said of her Charmed costar in a statement to Entertainment Weekly. "She was a talented actress, beloved by many, and the world is less without her. My condolences to all who loved her."

"A true lion heart," the actress, who replaced Shannen on Charmed in 2001 after she left the series, wrote in a comment on the late star's final Instagram post. "What a warrior. Your daddy is holding his best girl now."

She continued, "Love to your mama, your dog and all who love you fiercely. Love to Holly [Marie Combs]. Love to all of your legions of fans that I know you loved right back. If there was anyone who looked squarely at death and said no thanks, it was you dear Shannen. My head bows to you brave one. All love forever."

"You showed me what strength is," the actor, who played Leo Wyatt on Charmed, shared on Instagram. "You taught me to be fearless and live with purpose. To know your value and stick to your determination."

"Forever loved!" he added. "Truly heartbroken."

"I am absolutely heartbroken over the passing of Shannen Doherty." the Newsroom alum wrote on her Instagram Stories July 14. "When I was first diagnosed with breast cancer I remembered how she bravely let the world into her journey and reached out to her. We became instant friends- which I honestly couldn’t comprehend at times because watching her on 90210 was everything to me when I was 10."

"We bonded through a shared battle and a desire to help other women," she continued. "Looking back on the last text she sent me just a couple months ago, she asked how I was doing and if she could do anything for me… true to form, Shannen was offering her support even though she was in the final stage of fighting this horrific disease."

Olivia concluded her statement with a heartfelt message to her late friend. "Cancer is really f--king scary and Shannen faced it with such dignity, strength and grace," she expressed. "I’m sending all of my love to her mother who was her best friend, hero and champion every step of the way. Fly so high, my friend."

"Thank you for being here," the actress, who is battling multiple sclerosis, commented on Shannen's final Instagram post. "Thank you for showing us how to keep going. Rebel heart."

"Love you," the actress wrote in a comment on Shannen's last Instagram post. "Fly high lovely kind sweetheart woman. This hits hard. Your heart,courage and kindness will be so missed."

"Your bravery and ability to share your Cancer journey left something 'in' people," the Oscar winner wrote on Instagram. "Rest well. God bless your loved ones."

The actor, who guest starred on Beverly Hills, 90210 as Rick, who Shannen's character Brenda dated briefly after meeting him in Paris, wrote on X, "RIP Shannen," adding a crying emoji.

The Wicked star wrote in an Instagram comment, "Fly with the angels sweet precious soul!"

"My heart is broken," he wrote on Twitter. "It was a pleasure to meet Shannen Doherty while filming our movie Fortess a little over 2 years ago! She was full of warm energy and positive vibes. So young. So talented. May she rest well."

"RIP Shannen Doherty," he wrote on X, formerly Twitter. "I met her during the Full House days. She was lovely and had a beautiful smile. Today, I’ll also think about the women in my life who all succumbed to cancer - my mom, my sister, Sharon and my niece, Shannon, who all were so strong and so beautiful."

Alongside an article reporting Shannen's passing, the journalist wrote on Instagram, "I'm so sad to hear this news..."

"Such sad news," the Community actress wrote on Twitter. "I was hoping she would beat the disease again."