Recently, a new class action lawsuit is taking aim at Monday Haircare, alleging that the brand misleads consumers by underfilling its popular haircare products.
Filed on July 25 in California federal court by plaintiff Silvia Garcia, the suit claims that Monday sells products in oversized opaque bottles that appear full but contain significantly less product than the packaging suggests. Garcia says she purchased Monday’s Moisture + Hyaluronic Acid Shampoo from a Target store in May 2025 and was disappointed to find a large amount of empty space in the container. She argues that she would not have paid a premium price for the product had she known it was underfilled.
The complaint calls Monday’s practice a “slack-fill scam,” alleging that the opaque 12-fluid-ounce containers make it impossible for consumers to accurately assess the quantity they are purchasing. While the net weight is disclosed on the label, Garcia contends that shoppers reasonably expect the container size to reflect the actual amount of product inside.
According to the lawsuit, these packaging practices not only deceive customers but also give Monday an unfair advantage over competitors who label and fill their products accurately. The case points out that California courts have previously found similar slack-fill claims valid and appropriate for class action treatment.
Monday Haircare, known for its minimalist packaging and popularity on retail shelves, has not yet responded to the lawsuit.
