The analysts expected the company's initiatives would help improve profits over time. But after Thursday's earnings release, "it is clear some challenges could be longer lasting," analyst Olivia Tong and her team said in a Friday note.
The report cited negative price pressures in every segment for the latest quarter, a disproportionate hit to the company from industry destocking and rising costs for consumer packaged goods companies.
The BofAML analysts also cut their price target on the stock by $8 to $82 a share, which is still more than 9 percent above where the shares closed Thursday.
P&G shares fell more than 1 percent to near $74 a share at the open Friday, after dropping more than 3 percent Thursday.
The Dow component reported earnings Thursday morning that topped expectations. But P&G said it expected organic sales growth for 2018 to fall in the low end of a 2 to 3 percent range, and analysts worried about declining market share.
"PG is taking steps to improve its growth profile, including [Thursday's] deal to acquire Merck Consumer Health, and there are pockets of growth like Beauty," the BofAML analysts said, "but not meaningful enough in total against the challenges."
As of Thursday's close, shares of P&G were in a bear market, off 20.8 percent from their record high hit in September of $94.67 a share.
— CNBC's Lauren Hirsch contributed to this report.