CVS and Walgreens are completely dominating the US drugstore industry

The days of filling your prescription at your local mom-and-pop pharmacy are almost gone.

Today, two chains - CVS and Walgreens - together control at least half the drugstore market share in almost every major US city.

In a report on the US drug industry released Tuesday, Barclays' Meredith Adler provided some data on drugstores in the 100 largest metro-areas in the United States.

Among the most striking statistics is that CVS and Walgreens together control between 50 and 75 percent of the drugstore market in each of the country's 14 largest metro-areas.

This includes New York, Los Angeles, Chicago, Dallas/Fort Worth, Houston, Philadelphia, Washington DC, Miami, Atlanta, Boston, San Francisco, Phoenix, Riverside/San Bernardino CA, and Detroit. These areas are home to more than 100 million Americans.

Walgreens' 8,200 US locations together with CVS' 7,800 also hold at least 50% of the market share in 70 of the top 100 metro-areas in the country.

CVS will soon gain even an even larger share in US markets as the company announced in June that it will be purchasing more than 1,660 Target pharmacies across the country. CVS will operate these pharmacies from within the big-box retailer.

Walgreens (and its Duane Reade subsidiary) alone controls more than half the market in cities like Chicago, St. Louis, Milwaukee and Memphis. Meanwhile, CVS does the same in Washington DC, Boston, Providence and Honolulu - where the chain has more than 75% of the market.

While these two companies clearly dominate the drugstore industry in the US, Rite Aid and Walmart, the 3rd and 4th largest drugstore chains, respectively, also have significant market shares in many major cities.

At a time when US healthcare spending is expected to continue to rise, this enormous market control will likely prove to be incredibly valuable for all of these companies.

Check out the chart below to see how much market share these four companies hold in the nation's 12 largest metro-areas.