Estee Lauder was downgraded from overweight to neutral by Piper Jaffray, who says teenagers are wearing less makeup and changing their shopping habits.
Cosmetic sales are soft due to a combination of beauty categories like skincare and hair care competing for customers, a shift to single-item, multi-use products and younger shoppers choosing minimal or no make up, analysts said.
The "VSCO girl" trend — which includes a more natural look that requires fewer beauty products — was the go-to look for teenagers heading back to school this year, analysts Erinn Murphy and Eric Johnson said in a research note.
The trend is unusual, experts say, because it focuses on owning a specific set of products that encourages strong brand associations among teenagers. VSCO girls care about lip glosses from companies like Glossier, Burt's Bees and Carmax and facial sprays from Mario Badescu and Too Faced, the analysts at Piper said. Independent brands continue to pop up and take a share of the market.
In Piper Jaffray's fall teen survey this year, the firm found that cosmetics spending was down 21% year-over-year — the lowest it has been in nine-and-a-half years.
The prestige cosmetics market, which includes brands like Estee Lauder's MAC and Bobbi Brown, has been soft since the end of 2017 and into 2018, according to data from the NPD Group. In the second quarter of 2019, prestige makeup was down 4%. The analysts said they believe trends have decelerated further through September.
Although skincare, which makes up 44% of Estee Lauder's sales, remain globally healthy, Murphy and Johnson said they do not believe the cosmetics company is immune to further slowdown in the industry.
But the VSCO girl trend does not mean all is lost for Estee Lauder. Piper Jaffray noted that the company's cosmetic retail sales in China remain strong despite trade tensions.
"We continue to believe EL has significant room to grow from here," the analysts wrote. The brands La Mer, MAC and Origins were "extremely strong" in the first quarter, they added.
China has been a big driver for the beauty industry for the past few years. A report from J.P. Morgan earlier this month found that China is expected to overtake the United States in beauty sales by 2023, even if its current growth slows, and prestige cosmetics companies like Estee Lauder are benefiting. According to the report, as of June, Estee Lauder grew more than 40% in China over the past year, on top of the 67% growth seen in the previous 12 months.
Estee Lauder did not immediately respond to CNBC's request for comment.
The company's stock has gained nearly 43% since the start of 2019. Shares, which have a market value of $67 billion, were down about 1% in trading on Monday.
Correction: In the second quarter of 2019, prestige makeup was down 4%, according to NPD Group. An earlier version of this story misstated the time period in which sales fell.