A year after last seeing her, 31-year-old drug addict Margaret "Molly" Wheeler walks to her mother Deb's house remembering times before her fall. She insists that she is ready to be sober and begs her mother to allow her to stay for a few days before going to detox. Deb, although ambivalent about the matter, stands resolute with the support of her husband Chris, fearing that aiding Molly in any way will serve as being an enabler. Molly spends the night outside her mother's house and is persistent about her recovery. The next morning a frustrated Deb agrees to take Molly to detox. Upon arrival, it is revealed that Molly has been an addict for over a decade, has lost custody of her children, and is on her 15th attempt at sobriety. Four days after commencing detox, she is offered an opioid antagonist in order to help her on the road to sobriety. However, she must stay off any drugs for an additional four days before it is safe for her to receive the first shot, and then expect an additional shot each month.
On her first day at home, Molly learns through Deb about many of her misdeeds during her time as an addict, many of which Molly clearly regrets. Deb remains suspicious of Molly's intentions, but by the end of the day, secretly begins to have hope.
On the second day, Sean, Molly's ex, allows her to see their children. Although, initially reluctant, they are happy to see her and make the most of their time together. She and Deb go grocery shopping, where they see Coach Miller, who invites Molly to speak to her class about drug addiction. Back at home, Deb reveals she was very unhappy with Molly's father, Dale, as she felt forced into marriage after becoming pregnant with Molly's older sister, Ashley, and this led to her walking out on the family. Molly has always held this abandonment against Deb and blames her addiction on these events. Deb dismisses this, admitting that Dale's implied mental and emotional abuse was the reason for her leaving, much to Molly's surprise.
Molly speaks to Coach Miller's class on her third day at home. While speaking to the class, she releases her emotions, and is blatant and transparent with the children about her situation and experiences, using the moment to vent. This causes Deb to openly express her optimism and hopes that this time, Molly will finally recover. Afterwards, Molly asks that Deb take her to see Sammy, a friend and fellow addict. There, Deb has a chance encounter with Molly's ex-boyfriend Eric, who inadvertently reveals that Molly was pregnant. Molly later confesses to Deb that she was pregnant, but gave the baby up for adoption. That evening, Molly receives a phone call from the detox center and learns that due to issues with her health insurance, she cannot get the shot until Monday, adding an additional three days to her wait and thus the fight against her urges. A suspicious Deb questions the call, they argue, and Molly leaves with Sean.
The additional days become excruciating for Deb as she attempts to contact Molly incessantly to no avail. On Monday morning, Molly arrives at the house urging Deb to get ready so they will not miss her appointment at the detox facility. However, before they leave Molly asks Deb for her urine, confirming Deb's suspicions. Molly further admits that she has relapsed. Despite this, she is adamant that she does wish to get sober, and Deb provides her urine. At the center, Molly receives the opioid antagonist shot, but due to her having drugs in her system, she goes into acute withdrawal, and they rush to the hospital.
Four months later, Molly is still living with Deb, visits her children regularly, is getting ready for her next shot, and is on her way to recovery. The film ends with a line about the real-life mother and daughter who inspired the film, Amanda Wendler (Molly) and Libby Alexander (Deb).
On April 23, 2021, "Somehow You Do", the lead single from the movie's soundtrack, was released. The song was written by Diane Warren and performed by country star Reba McEntire, who noted on her Instagram that she was "so proud to be associated with these three very powerful women", referencing Warren, Close and Kunis.[7] "Somehow You Do" was nominated for an Academy Award for Best Original Song.[8][9]
On Rotten Tomatoes, the film has an approval rating of 56% based on 79 reviews with an average rating of 5.80/10. The site's critical consensus reads, "Four Good Days struggles to bring authenticity to its tragic source material and strands its talent in a bland melodrama."[12]Metacritic assigned the film a weighted average score of 53 out of 100, based on nine critics, indicating "mixed or average reviews".[13]