In May 2004, M&M's ran a Shrek 2 promotion to tie in with the film's release. M&M's were offered "ogre-sized" (65% larger) in swamp/ogre colors. They were sold at many stores displayed in huge cardboard-cutout ogre displays. Coe, Sophie D.; Coe, Michael D. (2019). The True History of Chocolate. London: Thames and Hudson. ISBN 978-0-50029-474-1.

Sloane 2016:"In 1887, after many unsuccessful experiments, Daniel Peter developed the original formula for what was to become the first successful milk chocolate in the world. He called his product Gala after the Greek word meaning 'from the milk'" Topik, Steven (2006). From Silver to Cocaine: Latin American Commodity Chains and the Building of the World Economy, 1500–2000. Duke University Press. pp.189–191. ISBN 0822388022. In 2007, M&M's introduced a limited-edition raspberry flavor called "M&M's Razzberry Chocolate Candies". The Story of M&M's Brand". mms.com. Mars, Incorporated. Archived from the original on April 9, 2008 . Retrieved June 14, 2008. In 1875, the Swiss entrepreneur and chocolatier Daniel Peter, based in Vevey and related to the Cailler family, first successfully combined cocoa mass, cocoa butter, and sugar with condensed milk (recently created by his neighbour and friend Henri Nestlé) to produce milk chocolate. [9] The process was further refined by another Swiss chocolatier, Rodolphe Lindt, who developed the conche in 1879, which created a smoother product. [10] However, it is only after many years of fine-tuning that the original formula was developed and, in 1887, the Gala Peter brand was finally launched. Daniel Peter called his product 'Gala' after the Greek word meaning 'milk'. [11]Most M&M varieties are technically gluten-free and typically have the same base ingredients (like milk, soy, and chocolate). However, M&Ms are not distinctly advertised as gluten-free – and Mars Wrigley has never stated that they’re processed on separate equipment from gluten-containing products. Therefore, cross-contamination is something to consider. Newquist, H.P. (2017). The Book of Chocolate: The Amazing Story of the World's Favorite Candy. Penguin Books. p.98. ISBN 9781101635179. During the Easter season, it’s hard to resist M&M Eggs. Their crispy shells and milk chocolate interior should be safe for people on a gluten-free diet. M&M's (stylized as m&m's) are color-varied sugar-coated dragée chocolate confectionery, each of which has the letter "m" printed in lower case in white on one side, consisting of a candy shell surrounding a filling which varies depending upon the variety of M&M's. The original candy has a semi-sweet chocolate filling which, upon introduction of other variations, was branded as the "plain, normal" variety. Peanut M&M's, which feature a peanut coated in milk chocolate, and finally a candy shell, were the first variation to be introduced, and they remain a regular variety. Numerous other variations have been introduced, some of which are regular widespread varieties ( peanut butter, almond, pretzel, crispy, dark chocolate, and caramel) while others are limited in duration or geographic availability. M&M's are the flagship product of the Mars Wrigley Confectionery division of Mars, Incorporated. Chocolate". The American Heritage Dictionary. Archived from the original on 17 May 2008 . Retrieved 9 May 2009.

Melina, Remy (February 10, 2011). "Why Were Red M&M's Discontinued for a Decade? LiveScience". Live Science. Archived from the original on May 23, 2018 . Retrieved May 22, 2018. Meo, Carlo (2012). Design marketing. Innovare cambiando i significati del consumo (in Italian). Milan: Gruppo 24 Ore. ISBN 9788863454413. a b c Olsen, Elizabeth (June 21, 2010). "A Campaign for M&Ms With a Salty Center? Sweet". The New York Times. Archived from the original on August 15, 2019 . Retrieved August 15, 2019.Smee, Taryn (August 8, 2018). "Candy Wars: Did M&M's Steal their Concept from Smarties?". The Vintage News . Retrieved November 1, 2023.

Review: Cinnamon M&M's". The Implusive Buy. November 3, 2011. Archived from the original on March 26, 2019 . Retrieved September 6, 2019. In 1949, the brand introduced the tagline "The milk chocolate that melts in your mouth, not in your hand." [15]Behind The Voice Actors M&M's – Voice of Red". Behind the Voice Actors. Archived from the original on November 14, 2012 . Retrieved April 26, 2012. Smith, Andrew F. (2002). Peanuts: The Illustrious History of the Goober Pea. University of Illinois Press. ISBN 9780252025532.

Smith, Andrew F. (2011). Fast Food and Junk Food: An Encyclopedia of What We Love to Eat. Santa Barbara: Greenwood. ISBN 978-0-31339-394-5.

In 2008, two limited-edition varieties of the candy were introduced – "Wildly Cherry" M&M's, and, as a marketing tie-in with the film Indiana Jones and the Kingdom of the Crystal Skull, "Mint Crisp" M&M's. Kane, Courtney (June 29, 2000). "THE MEDIA BUSINESS: ADVERTISING; M&M/Mars concludes, after 46 years, that 'Plain' does not do justice to the original M&M's candy". The New York Times. Archived from the original on March 5, 2016 . Retrieved July 27, 2016. Mendoza, Jordan (October 3, 2022). "For the first time in over a decade, a new M&M color: Meet Purple, who represents 'acceptance' ". USA Today . Retrieved April 30, 2023. Sethi, Simran (27 November 2017). "For those who think white chocolate isn't 'real' chocolate, have we got bars for you". The Washington Post . Retrieved 26 March 2023.