City Attorney Dennis Herrera’s attempt to curtail Monster Beverage Corp. from marketing its highly caffeinated energy drinks to minors is getting heated, with the company going to federal court to try to stop Herrera’s investigation. 
 
 In a lawsuit filed Monday in U.S. District Court in Los Angeles, Monster says Herrera’s effort would “impose undue burdens on interstate commerce” and violate constitutionally protected “commercial speech” and other rights. 
 
 The lawsuit also contends that “(Herrera) appears to be motivated by publicity rather than science.” 
 
 Herrera has been investigating the Corona (Riverside County)-based maker of Monster Energy drinks since October under the state’s unfair competition law, targeting its marketing claims that the amount of caffeine in its products is “completely safe” and that consumers “can never get too much of a good thing!” 
 
 In March, Herrera joined a group of 18 doctors from medical centers across the country in calling for the U.S. Food and Drug Administration to regulate caffeine levels in energy drinks, saying the beverages pose health risks, particularly for youths. 
 
 Under current FDA standards, caffeine in sodas can register no higher than about 71 milligrams per 12-oz. serving. Energy drinks often have between 100 and 300 milligrams of caffeine per 8-oz. serving and are often sold in much larger quantities per can, according to the doctors’ letter. 
 
 “The best available scientific evidence demonstrates a robust correlation between the caffeine levels in energy drinks and adverse health and safety consequences, particularly among children, adolescents, and young adults,” according to the doctors’ letter, which included signatories from Johns Hopkins University School of Medicine, UC Berkeley’s School of Public Health and UCSF’s pediatric and cardiology divisions 
 
 Monster markets to children as young as 6 years old, according to Herrera’s office, which produced screen shots from the beverage company’s “Monster Army” website listing an 11-year-old as a “Monster Army Major” and a 6-year-old as a “Reserve.” 
 
 The company, in its lawsuit, maintains that its product has less than half the caffeine of a Starbucks coffee. 
 
 “Today, any child can walk into a Starbucks and buy an unlimited number of ‘Grande’ (16-oz.) brewed coffee drinks-each one with more than twice the caffeine (330mg) as one of (Monsters’) 16-oz. energy drinks-with no restrictions or limitations,” the company’s attorneys wrote. 
 
 That is not the same thing, according to Herrera’s office. 
 
 “Starbucks isn’t marketing sweet drinks that are highly caffeinated to young people,” Herrera spokesman Matt Dorsey said. “The scientific consensus is these products are not safe for children.” 
 
 Herrera, in a statement, vowed to aggressively fight what he termed “an apparently pre‐emptive lawsuit.” 
 
 “Monster Energy is claiming an unfettered right to continue marketing its products to children and youth, even in the face of overwhelming evidence that its products pose serious risks to young people’s health and safety,” said Herrera. “I intend to litigate this case aggressively to reform their irresponsible marketing and business practices, which I believe clearly violate California’s consumer protection laws.” ||||| New York's attorney general is investigating whether the multibillion-dollar energy-drink industry is deceiving consumers with misstatements about the ingredients and health value of its products. 
 
 Eric T. Schneiderman issued subpoenas in July to PepsiCo Inc., maker of AMP, Monster Beverage Corp., and Living Essentials LLC, maker of 5-hour Energy drink, according to a person familiar with the matter. The subpoenas asked for information on the companies' marketing and advertising practices. 
 
 The caffeine-heavy, carbonated beverages have become ubiquitous at grocery stores, gas stations and checkout counters across the country. Makers of the drinks, which are often sweetened with flavors such as grape or mixed berry, say they boost energy with a mix of additives including B-vitamins, taurine and ginseng. AMP's website, for example, says the B-vitamins and caffeine in its Boost drinks offers "the kick you need to tackle the early morning meeting." On its website, 5-hour Energy says it gives "hours of energy" with "no crash later." 
 
 The probe is the latest in a series of attention-getting moves by New York officials. In May, New York City Mayor Michael Bloomberg announced plans to restrict the sale of large sodas at restaurants, movie theaters and other locations, sparking criticism from the beverage industry. This month, New York's top banking regulator, Benjamin M. Lawsky, accused British bank Standard Chartered PLC of illegal dealings with Iranian entities, and the bank agreed to a $340 million settlement. 
 
 Energy drinks are among the fastest-growing products in the beverage sector. U.S. retail sales of the drinks rose 16% last year to $8.9 billion, accounting for 12% of the carbonated-soft-drink category, according to Beverage Digest, a trade publication and data service. Monster leads in the U.S. by volume, ahead of Austria's Red Bull GmbH and Rockstar Inc. 
 
 The drinks are regulated more loosely than traditional sodas such as cola. In 2009, the Food and Drug Administration said it was "concerned" certain ingredients such as botanical extracts were being added to beverages and foods beyond their traditional use, which it said raised questions about safety. The federal agency says the term "energy drink" isn't defined by any FDA regulation, describing it as an ill-defined marketing term with widely varying ingredients. 
 
 The New York probe is focused on whether the drink makers are misleading consumers with inaccurate labeling and advertising, according to the person familiar with the matter. The investigation is in the early stages and could expand to other companies, that person said. 
 
 Spokespeople for PepsiCo, Monster and Living Essentials declined to comment. 
 
 Investigators are examining whether the companies overstated the benefits of exotic-sounding ingredients while understating the role of caffeine, a common stimulant that industry critics believe to be the main active ingredient, that person said. 
 
 The products' labels often don't say how much caffeine is contained in the drink. The label on Monster's 16-ounce can says it contains caffeine but doesn't say how much; 5-hour Energy doesn't say how much caffeine is contained in one bottle, but its website says it is about as much as a cup of coffee. 
 
 The Monster spokeswoman said that on a per-ounce basis, Monster contains half the caffeine of some cups of coffee. "Monster energy drinks are completely safe, and we stand behind our products," she said in an email. AMP's label says it contains 10 milligrams per fluid ounce. 
 
 Investigators are looking into whether the addition of ingredients like guarana—another source of caffeine—violates laws that ban putting multiple sources of caffeine in one beverage without disclosing the overall amount, according to the person familiar with the investigation. 
 
 If energy-drink makers are found to have violated certain New York state laws regulating food and drugs, they could be forced to pay civil fines and penalties, and to change their labeling and marketing. 
 
 Enlarge Image Close Bloomberg New York state is probing the energy-drink industry over the ingredients and health value of the products. Above, cans of Monster. 
 
 While the FDA generally has jurisdiction to regulate food and drink safety, state attorneys general also have powers to investigate and regulate almost any product sold within the boundaries of their states. 
 
 California-based Monster disclosed in an Aug. 9 Securities and Exchange Commission filing that it received a subpoena in July as part of an unnamed state attorney general's probe into the "advertising, marketing, promotion, ingredients, usage and sale" of its energy drinks. 5-hour Energy disclosed in a July bond-offering memorandum a state attorney general recently requested documents about its product and marketing. 
 
 Those disclosures are related to the New York attorney general's probe, people familiar with the matter said. 
 
 Some scientists and health experts say energy drinks deliver all their kick from caffeine, and that other ingredients, while not appearing to be dangerous, are simply a marketing gimmick. It is safe for the average person to consume about 400 milligrams of caffeine per day, but overconsumption could cause heart problems, according to health experts. 
 
 "You're better off drinking a cup of coffee," said Tod Cooperman of ConsumerLab.com, which has conducted a chemical analysis of 5-hour Energy and other energy drinks. A study Mr. Cooperman conducted on 5-hour Energy found it contains 207 milligrams of caffeine, far more than a typical cup of coffee's 80-100 milligrams. "It's a stimulant," he said of 5-hour Energy. 
 
 —Matthieu Wirz contributed to this article. 
 
 Write to Reed Albergotti at reed.albergotti@wsj.com and Mike Esterl at mike.esterl@wsj.com 
 
 A version of this article appeared August 28, 2012, on page A1 in the U.S. edition of The Wall Street Journal, with the headline: New York Probes Energy-Drink Makers. ||||| The American Medical Association may throw its clout behind sales and advertising bans of “high-energy/stimulant drinks” to young people under age 18, pending more scientific study about health risks. 
 
 A debate schedule for this weekend by the AMA’s policy-making House of Delegates comes amid intensifying scrutiny of energy drinks, which are popular particularly among young adults who get a boost from caffeine and other ingredients in the beverages. 
 
 But a resolution from the New York State Medical Society that will be discussed at this year’s annual AMA meeting in Chicago cites an increase in emergency room visits the physicians said was “linked to the consumption of ‘stimulant’ drinks.” Doctors have also cited probes like that of the New York State Attorney General’s investigation into drink makers that include Monster Beverage Monster Beverage Corp. (MNST) and PepsiCo PepsiCo Inc. (PEP). 
 
 Though any action this weekend by the AMA’s policy-making House of Delegates has no legal authority over the sale of high-energy drinks, the national doctor’s group has a bully pulpit on public health issues. The AMA is also considered a powerful lobby in Washington and in state capitols across the county where it holds sway when it comes to medical policy and health regulations. 
 
 “The popularity of stimulant drinks has increased markedly in recent years with sales increasing 240 percent from 2004-2009, with further data indicating that these drinks are consumed by 30 to 50 percent of children, adolescents, and young adults,” the New York delegation to the AMA House of delegates said in its resolution. “Studies have shown that high ‘stimulant’ drinks contain excessive amounts of caffeine with one can having the equivalent of up to 50 cups of coffee. Excessive caffeine can cause adverse effects such as dizziness, insomnia, agitation, restlessness, anxiety, GI disturbances, myocardial infarction and death.” 
 
 Any push by the AMA could meet resistance from drink makers. 
 
 Monster, for example, earlier this year has fought back against curbs on sales of its drinks such as a suit it filed against the San Francisco City Attorney this spring. Monster has also said labeling on its drinks caution that the beverages are “not recommended for children, pregnant women or people sensitive to caffeine,” according to an April report in the Wall Street Journal linked here. 
 
 The resolution regarding energy drinks is among dozens that will be debated at the AMA’s 524-member House of Delegates, which convenes Saturday to Wednesday at the Hyatt Regency Chicago. 
 
 Aside from endorsing a ban on such drinks, AMA delegates are also pushing for more scientific study of energy drinks. 
 
 On June 18, the AMA’s policy-making House of Delegates adopted policy supporting a ban on the marketing, but not on the sale of “high stimulant/caffeine drinks to adolescents under the age of 18. Here’s a link to AMA statement on the new policy. 
 
 Said AMA board member Dr. Alexander Ding, “Energy drinks contain massive and excessive amounts of caffeine that may lead to a host of health problems in young people, including heart problems, and banning companies from marketing these products to adolescents is a common sense action that we can take to protect the health of American kids.”
– San Francisco's city attorney wants Monster Beverage to cut down on both the caffeine in its energy drinks and the marketing of them, and the company is fighting back in federal court. Monster sued the office of Dennis Herrera this week, arguing that its drinks are no more harmful than a cup of Starbucks coffee and making the case that only the FDA can regulate the market, reports the Wall Street Journal. One thing in particular that irritates Herrera is that the company has a Monster Army website for kids that shows an 11-year-old "Monster Army Major" and a 6-year-old "Reserve," reports the San Francisco Chronicle. So, yes, the energy drinks have less caffeine than a cup at Starbucks, but the coffee chain "isn’t marketing sweet drinks that are highly caffeinated to young people,” says a Herrera spokesperson. The legal fight comes amid heightened scrutiny of energy drinks not only by the FDA but by New York state in particular.