Isabella Strahan is dealing with a new side effect during her cancer treatments.

Michael Strahan's daughter—who was diagnosed in October with medulloblastoma, a malignant tumor on the base of the brain—shared that new medications she's taking is affecting her memory, leading to full days that are seemingly wiped from her mind.

"I don't remember Tuesday," Isabella said in a video posted to her YouTube channel May 22, "'cause I'm given this drug to protect my hearing and just because I have a reaction to it, they give me Ativan. And for some reason—this happened last time too—I can't remember a single thing about that day."

She said in her May 21 video update that she began taking Ativan (also known as Lorazepam) to help combat effects of the other drug. She explained that the unnamed medication—which is in clinical trials, according to the teen—protects her hearing but makes her experience?? "rigor," meaning she starts shaking and gets very cold.

And while in that same video update, the 19-year-old also could also be seen enjoying a sandwich, she added that she didn't "remember ordering" it. But after the rigor set in, she said, "I guess I ordered myself a sandwich."

The University of Southern California student has been keeping fans updated with her vlogs throughout her battle with brain cancer, noting this week she will be done with her chemotherapy treatments very soon.

"Tomorrow's really my last day of chemo," she said in a May 21 clip. "It's crazy and then it's my last cycle and then I'm done. It's insane."

And even though she knows there's a light at the end of the tunnel—and that the light is coming sooner than she expected—she can't help but feel nervous.

"That's the thing, I just wait around for the next time I get chemo and I'm kind of scared," she explained in her May 22 post-chemo update. "Once I'm done, how I'm gonna go back to normal life? ‘Cause I feel like there's always gonna be another treatment or something I have to do."

She added, "Otherwise, I'm doing good."

To learn more about Isabella's cancer journey, keep reading.

Isabella Strahan—the daughter of former couple Michael Strahan and Jean Muggli—said she "didn't notice anything was off" about her health until early October 2023, when she started experiencing headaches and nausea.

After throwing up blood one day, she got a full checkup and MRI scan at the urging of her dad. The results showed medulloblastoma, a malignant brain tumor found in children.

Later that month, she underwent brain surgery to remove the mass.

Isabella went public with her diagnosis in a January 2024 interview with her dad and ABC News' Robin Roberts.

"I literally think that in a lot of ways, I'm the luckiest man in the world because I've got an amazing daughter," Michael noted at the time. "I know she's going through it, but I know that we're never given more than we can handle and that she is going to crush this."

Isabella's twin sister Sophia Strahan also offered her support. "I'm so lucky to have the most amazing sister and best friend in the world," she wrote on Instagram. "The last few months have been so much harder than we could have ever imagined, but it's made me realize just how strong you are"

Following her interview, Isabella shared she had finished her round of radiation therapy.

"I'm very excited to finally be done," she said in a Jan. 16 YouTube video. "It's been a long six weeks and I'm very happy to finally heal my head after all of this because the side effects and everything get to you."

Following radiation therapy, Isabella began undergoing chemotherapy to treat her cancer.

"My whole mouth feels like I got one giant root canal," she shared in a Feb. 16 vlog. "Every single tooth, just ripped out and not even surgically put back in. My jaw hurts, the bottom of my tongue hurts. It hurts when I gulp water." 

Still, the teen kept her spirits up, joking in a video posted a week later that her hair is "insufficient now."

"Besides being bald," she said, "it doesn't bring me pain mentally." 

Though Isabella was initially scheduled to undergo her second round of chemotherapy in early March, she underwent emergency surgery on her skull—during which doctors drained out extra fluid from her head and replaced a bone they had originally cut out with a titanium plate—which pushed her chemo back by weeks.

"I'm in so much pain," she said in a March 6 vlog. "My face is extremely puffy, and this sucks. I was in so much pain earlier. I was, like, screaming."

Isabella's dad Michael arranged for her favorite singer Bryson Tiller to stop by their New York City home as a pick-me-up amid her treatments.

"You haven't moved this much in months!" Michael joked to his daughter in her vlog of the visit. "You are fangirling right now."

Isabella shared in a March 21 video that she had started her second round of chemotherapy, meaning there was "just four more" rounds to go.

Amid her second chemotherapy round, Isabella said she began experiencing difficulties in walking.

"I literally can't walk without being lightheaded or out of breath," she shared in a March 27 vlog, lamenting that there isn't an "anti-exhaustion medicine" she could take.

The YouTuber had a positive update after finishing her second round of chemotherapy, sharing that she would only have to undergo two more rounds of instead of the originally scheduled four.

"These are happy tears," she said in a video posted April 10. "It's not even considering crying when it's happy tears."

However, Isabella hit a bump in the road in her treatment plan when she had to undergo a third craniotomy. According to the teen, this procedure was unlike anything she had previously experienced.

"Not going to lie, I've been crying a lot," she detailed in an April 12 vlog. "They sunk a needle in three spots and drained fluid, and I was completely awake for this. So, my first completely awake surgery."