Marijuana and other products containing THC, the plant\u2019s main psychoactive ingredient, have grown more potent and more dangerous as legalization has made them more widely available.<\/p>\n

Although decades ago the THC content of weed was commonly less than 1.5%, some products on the market today are more than 90% THC.<\/p>\n

The buzz of yesteryear has given way to something more alarming. Marijuana-related medical emergencies<\/a> have landed hundreds of thousands of people in the hospital and millions are dealing with psychological disorders linked to cannabis use, according to federal research.<\/p>\n

But regulators have failed to keep up.<\/p>\n

Among states that allow the sale and use of marijuana and its derivatives, consumer protections are spotty.<\/p>\n

\u201cIn many states the products come with a warning label and potentially no other activity by regulators,\u201d said Cassin Coleman, vice chair of the scientific advisory committee of the National Cannabis Industry Association.<\/p>\n

The federal government has generally taken a hands-off approach. It still bans marijuana as a Schedule 1 substance \u2014 as a drug with no accepted medical use and a high chance of abuse \u2014 under the Controlled Substances Act. But when it comes to cannabis sales, which many states have legalized, the federal government does not regulate attributes like purity or potency.<\/p>\n

The FDA \u201chas basically sat on its hands and failed to honor its duty to protect the public health,\u201d said Eric Lindblom, a scholar at Georgetown University\u2019s law school who previously worked at the FDA\u2019s Center for Tobacco Products.<\/p>\n

Pot has changed profoundly since generations of Americans were first exposed to it.<\/p>\n

Cannabis has been cultivated to deliver much higher doses of THC. In 1980, the THC content of confiscated marijuana was less than 1.5%<\/a>. Today many varieties of cannabis flower \u2014 plant matter that can be smoked in a joint \u2014 are listed as more than 30% THC.<\/p>\n

At one California dispensary, the menu recently included a strain posted as 41% THC.<\/p>\n

Legalization has also helped open the door to products that are extracted from marijuana but look nothing like it: oily, waxy, or crystalline THC concentrates that are heated and inhaled through vaping or dabbing, which can involve a bong-like device and a blowtorch.<\/p>\n

Today\u2019s concentrates can be more than 90% THC. Some are billed as almost pure THC.<\/p>\n

Few people personify the mainstreaming of marijuana as vividly as John Boehner, the former U.S. House speaker. The Ohio Republican long opposed marijuana and, in 2011, reportedly declared himself \u201cunalterably opposed\u201d to its legalization<\/a>.<\/p>\n

Now he\u2019s on the board of Acreage Holdings<\/a>, a producer of marijuana products.<\/p>\n

And Acreage Holdings illustrates the evolution of the industry. Its Superflux brand<\/a> markets a vaping product \u2014 \u201cpure live resin in a convenient, instant format\u201d \u2014 and concentrates such as \u201cbudder,\u201d \u201csugar,\u201d \u201cshatter,\u201d and \u201cwax.\u201d The company bills its \u201cTHCa crystalline\u201d concentrate as the \u201cultimate in potency.\u201d<\/p>\n

Higher concentrations pose greater hazards, according to the National Institute on Drug Abuse. \u201cThe risks of physical dependence and addiction increase with exposure to high concentrations of THC, and higher doses of THC are more likely to produce anxiety, agitation, paranoia, and psychosis,\u201d its website<\/a> said.<\/p>\n

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\n\t\t\t\t\t\t\tA sheet of \u201cshatter,\u201d a form of THC concentrate, is seen after being removed from the oven.\t\t\t\t\t\t(Brennan Linsley \/ AP)<\/span><\/figcaption><\/figure>\n<\/p><\/div>\n