Monday Haircare, the fast-growing beauty brand known for its pastel bottles, is facing legal action for allegedly misguiding customers with deceptive packaging.
According to a new class action lawsuit filed in California federal court, Silvia Garcia claims that Zuru LLC, doing business as Monday Haircare, engages in a “slack-fill scam” by selling haircare products in oversized, opaque bottles that are not actually filled as much as consumers expect.
Oversized Bottles and “Slack-Fill Scam”
The complaint, filed by Garcia on July 25, says that Monday Haircare’s packaging deliberately misleads buyers by making shampoos and conditioners look full when a “significant amount of empty space” is present inside. Garcia points to the 12-fluid-ounce Monday Moisture + Hyaluronic Acid Shampoo, which she purchased at a Target store in May 2025. When she opened the container, she found it had a lot less product than its size would suggest.
The opaque containers, according to the lawsuit, prevent shoppers from seeing the real fill level. Garcia alleges, even if consumers check the net weight of the product before buying, they would not expect the actual amount of shampoo to be significantly less than the size of the container suggests.
Misleading Consumers and Gaining Unfair Advantage
The class action complaint accuses Monday Haircare of using oversized, non-transparent packaging to give an impression of greater value, which unfairly harms buyers and puts honest competitors at a disadvantage. By not filling their bottles to match the package size, the brand can charge a premium while providing less product.
Garcia argues that “Defendant’s misleading and deceptive practices proximately caused harm to Plaintiff by causing Plaintiff to spend more money than Plaintiff would have otherwise spent had Plaintiff known the extent of the Product’s non-functional slack-fill.”
She also notes that, “Several California courts have found that cases involving nearly identical claims are meritorious and appropriate for class treatment.”
Who Is Included in the Suit?
The lawsuit seeks to represent a class of all consumers who purchased alleged underfilled haircare products from Monday in the past four years. The case focuses on popular items like Monday Moisture + Hyaluronic Acid Shampoo, but may include a wider range of the brand’s product lineup if the court grants class certification.
Broader Industry Implications
This case highlights a broader trend in the personal care and beauty industry, where “slack-fill” lawsuits—accusing brands of selling products in overlarge packages—are becoming more common. The Monday Haircare action mirrors allegations in other recent cases, such as claims against Farouk Systems that it falsely advertised its CHI and BioSilk haircare as made in the United States or containing natural ingredients.
Industry experts believe slack-fill lawsuits signal a renewed focus on transparency and truth-in-labeling, especially in the fast-moving beauty sector, where packaging is often key to consumer perception.
What’s Next for Consumers
If Monday Haircare is found liable, affected shoppers could receive restitution or refunds, and the company may be forced to change its packaging. For now, anyone who purchased underfilled Monday products in the past four years should stay alert for class action updates or settlement notices.
