Braun was considered a five-tool player for his ability to hit for power and average, his baserunning speed, and his excellent fielding and arm strength.

[4] However, Braun came under scrutiny for a testosterone test that he failed in 2011 and then for his connection in 2012 to the Biogenesis of America clinic that provided performance-enhancing drugs to professional baseball players.

On July 22, 2013, Braun was suspended without pay for the remainder of the 2013 season and playoffs (totaling 65 regular-season games) for violating the league's drug policy.

[16][17] During his junior year, his final and most successful at Miami, Braun batted .396 with 18 home runs, a .726 slugging percentage, 76 RBIs, and 23 stolen bases.

He was ninth in slugging and 10th in RBIs in NCAA Division I, and was named to Baseball America's 2005 College All-American Team as the designated hitter (DH).

[38] In mid-August, Brewers manager Ned Yost moved Braun from third in the batting order to cleanup, switching him with Prince Fielder.

[41] On September 9, the Brewers became the third team in major league history to start a game with three straight home runs, as Rickie Weeks, J. J. Hardy, and Braun homered in consecutive at bats.

[63] Braun's agent, Nez Balelo, crunched enough numbers to show him what he potentially could have made over the life of this contract if he had chosen not to sign it.

[71][72] After returning, on September 25 he hit his first grand slam, delivering a 2-out, 2–2 pitch from the Pirates' Jesse Chavez into the left field bleachers of Miller Park in the bottom of the 10th inning, winning the game 5–1, and keeping the Brewers' 2008 postseason hopes alive.

[73] Three days later, Braun helped put the Brewers into the postseason for the first time since 1982, by hitting a go-ahead 2-run homer in the bottom of the 8th against the Chicago Cubs.

[70][85][86] In 2008, in 151 games Braun hit 37 home runs (tied for 4th in the NL, behind Ryan Howard, Adam Dunn, and Carlos Delgado), with 106 RBIs (9th), and batted .285 with a .553 slugging percentage (5th).

[102] Braun was second all-time, with 79 home runs over his first two calendar years in the major leagues, to Phillies Hall of Famer Chuck Klein (83); ahead of third-place Joe DiMaggio and Mark McGwire (77).

[105] Braun's 103 home runs in his first three Major League seasons are sixth-most in baseball history, behind Pujols (114), Mark Teixeira (107), and three Hall of Famers—Kiner (114), Matthews (112), and Joe DiMaggio (107).

[113] Braun also became the eighth player in major league history with at least 100 runs, 100 RBIs, 200 hits, 30 homers, 20 stolen bases, and a .300 average in the same season.

[116] Braun was named NL Player of the Week for August 1–8, after leading the majors with a .538 batting average, 14 hits, and 8 runs scored, and notching a career-best five-hit performance in one game.

[133] He was named the NL Player of the Month for the fourth time in his career in September, after tying for second in the league with 8 home runs and 22 RBIs, while batting .330.

[146] On September 16, Braun hit his 200th career home run in his 867th game, against the New York Mets, faster than all but four active players in the Majors (Ryan Howard, Albert Pujols, Adam Dunn, and Alex Rodriguez).

[155] On July 14, 2017, Braun hit his sixth career grand slam, breaking a tie with Cecil Cooper, John Jaha, and Jeromy Burnitz for the most in Brewers history.

[164] Braun made his 12th career Opening Day start, tying Paul Molitor for second in team history, behind only Robin Yount (19).

[177][178][179][180] ESPN reported that Braun had tested positive for an elevated level of testosterone caused by a performance-enhancing drug and faced a 50-game suspension.

Sports reported that Braun's name appeared three times in records of Biogenesis of America, a Coral Gables clinic alleged to have distributed performance-enhancing drugs to a number of Major League Baseball players who tested positive for banned substances.

[192] On June 4, 2013, ESPN reported that MLB was preparing suspensions for players linked to using PEDs provided by Biogenesis of America and Bosch.

[193] On July 22, 2013, MLB suspended Braun for the remaining 65 games of the regular season, plus the entire postseason, for his involvement with the Biogenesis clinic.

MLB considered Braun's speech, as well as his earlier attacks on Laurenzi, to be conduct detrimental to baseball—an offense punishable under the collective bargaining agreement, not the drug policy.

General Manager Doug Melvin left him a voicemail, and after returning the call and learning of the team's plans Braun grabbed his outfield glove, and started taking fly balls.

"[226] In July, by which time Braun was being mentioned in the press as a Gold Glove candidate, Ed Sedar, the Brewers' outfield defense expert, said: "He probably has the best arm in baseball in left field.

"[237] In another coincidence, Braun lived for a time with his maternal grandfather in a house that previously belonged to Jewish Hall of Fame first baseman Hank Greenberg.

[255] In October 2008, Apple released a commercial for a new iPhone, that showed a clip of Braun's 10th-inning walk-off grand slam against the Pittsburgh Pirates on September 25, 2008, which kept the Brewers' Wild Card hopes alive.

[72][257] He has appeared in commercials for Muscle Milk, Dick's Sporting Goods, and regional convenience store chain Kwik Trip.

[260] In July 2012, Braun teamed up with Green Bay Packers quarterback Aaron Rodgers to open a restaurant, 8-Twelve, in Brookfield, Wisconsin.