The potency of drugs including marijuana in the U.S have increased dramatically in the last few years. KENZO TRIBOUILLARD/AFP/Getty Images

Marijuana and methamphetamine that are sold illegally in America have increased in strength, showed a report released on Oct. 23 by the Drug Enforcement Administration (DEA).

As Rosalie Pacula, the RAND Corporation drug-policy researcher said to the Los Angeles Times, the enhanced drugs come in the wake of the recreational drug marketplace getting more competitive, thanks to the rise in the popularity of opioids.

The DEA’s report mentioned that the higher the potency of drugs already available, the more pressure drug traffickers would be under to provide even stronger variants, hinting at a vicious cycle.

In the last few years, drug dealers in America have substituted the heroin that they used to sell with fentanyl. Fentanyl is considerably more potent, and also a lot more dangerous than heroin.

This has led to a rise in the number of overdose cases and deaths.

Marijuana — arguably a more popular drug than fentanyl — is giving users a greater and perhaps more dangerous high.

For instance, the average tetrahydrocannabinol (THC) concentration in the marijuana that the DEA seized in 1995 was 4 percent. But in 2015, the concentration was 11 percent. THC is the main psychoactive element in cannabis.

Hash oil is yet another substance that has gone up in potency. In 1995, the hash oil the DEA seized had a potency of 13 percent while in 2015, it was up to 56 percent.

Usually adults couldn’t overdose on THC. However, that’s not to say that spiked marijuana wouldn’t have any negative effects. For instance, users could get more intoxicated than they are used to from taking the same dose as usual, which could in turn adversely affect their decision-making skills while driving etc.

Marijuana-Spider Man
The potency of drugs including marijuana in the U.S has increased dramatically in the last few years. KENZO TRIBOUILLARD/AFP/Getty Images

Enhanced methamphetamine could be a significantly bigger problem.

With the entry of stronger methamphetamine in the market, even more overdoses could happen in the future.

To measure the potency of methamphetamine, the DEA compared the percentages of the molecules in the drugs that are in the shape called the D- isomer as opposed to those in the shape called the L-isomer.

The D-isomer is psychoactive (meaning, it could change brain function and potentially result in altered consciousness, perception, mood or behavior). The L-isomer isn’t psychoactive.

DEA records showed that the methamphetamine that it seized and tested in the first half of 2011 had 76 percent D-isomer on average. However, for the first half of 2016, the methamphetamine was 90 percent D-isomer.

Overdoses from psychostimulants like methamphetamine have increased in the same time period.

The most recent relevant data is from 2015. In that year, more than 5,700 Americans died from psychostimulant overdose. In 2011, the number of deaths was 2,300.

However, it’s not easy to ascertain from the above statistics alone if the increase in death toll by psychostimulant overdose is wholly attributable to more people using methamphetamine.

The reason is that the National Survey on Drug Use and Health — the foremost source for statistics on drug Habits in the U.S. changed how it enquired people regarding their methamphetamine use in 2015, meaning that the new numbers they present are no more comparable with the figures from the past.