Basic Care, Amazon’s private-label over-the-counter product, was the top brand in Amazon’s search results for the OTC allergy category from August 1 through August 15, according to data released by Kantar Media on Tuesday.

Kantar Media analyzed four popular allergy-related keywords such as “allergy pills,” “allergy medicine,” “allergy,” and “allergy relief.” The analysis ranks them based on the percentage of time the brand was found in the top three positions on the first search results page, the brand’s average page position and the number of the brand’s listings found.

“Over the past few years Amazon has been assembling a formidable stable of private-label brands categories ranging from apparel and electronics to home items and personal care,” writes Jim Leichenko, director of marketing at Kantar Media.

Leichenko writes that Amazon’s private labels are among the top brands in Amazon search results in a variety of product categories, and points to data from Piper Jaffray that projects this marketplace will more than triple its advertising business to about $16 billion by 2021.

Zyrtec ranked second in Amazon.com search results, followed by Claritin, GoodSense and Flonase.

From August 1 through August 15, Amazon private-label brands were among the most visible in the vitamins category. Amazon Elements, Solimo and Whole Foods’ 365 Everyday Value ranked No. 7, No. 8, and No. 9, respectively, on the top 17 vitamin keywords such as “vitamin D and “prenatal vitamins.”

Overall, Nature Made and Bronson were the top two advertisers in the vitamin category, but in the cold and cough medicine category, Amazon private-label brands were less prominent, although still present among the top 10 brands on the keywords “cold medicine,” “cough suppressant” and “cough syrup.” Out of 35 brands advertising on the keyword group, Solimo ranked No. 8, while 365 Everyday Value ranked No. 9, beating out two dozen other brands.