Kratom appears to be very safe in recreational doses. A person who consumes too much Kratom will experience nausea and vomit the consumed Kratom before they're body can absorb enough alkaloids to cause an overdose. There have been conflicting statements made on the amount of alkaloids needed to cause an overdose. Some pin the number at 5 grams, while others say as little as 800 milligrams could cause an overdose. When reading this, it is important to remember that these numbers are regarding pure alkaloids and not the plant matter itself. 800 milligrams of alkaloids is relatively close to 65 grams of plant matter, depending on the potency. Also remember, an overdose does not particularly mean death, it's a range in which there are significantly higher risks of life threatening problems. There have been no documented cases of overdose.

Side effects
Consumption of Kratom does have possible side effects such as nausea, constipation, sleep problems, and temporary erectile dysfunction. Extensive use can cause some problems such as insomnia, anorexia, weight loss, darkening of skin, and dry mouth.
There are reports of a small number of Kratom users in South-East Asia experiencing more severe problems from they're extensive consumption of the plant. Problems such as hallucinations, delusional behavior, aggression and schizophrenia seemed to plague some users. Some of these users were also using drugs such as alcohol, opiates and amphetamines as well. Any one of these drugs could have caused these severe symptoms, so it would be questionable to assume that Kratom caused these problems. Some of the people who did not use other drugs did display symptoms, but these were long time users, some as much as 40 years of daily heavy consumption. It seems unlikely that users outside South-East Asia face the same risks, as most recreational users don't consume anywhere near the same amount of Kratom as people from South-East Asia. It is recommended that new Kratom users start with smaller doses to avoid potential negative effects. Avoid driving and operating heavy machinery. Use caution when mixing psychoactives substances with Kratom. There appears to be no information regarding Kratom use and interactions with MAOI’s and SSRI’s, but if you take MAOI’s, do not use Kratom. People taking SSRI’s are advised to use caution when taking Kratom. Most people taking SSRI’s report no problems with Kratom.

Addiction
As far as addiction, almost any psychoactive substance can be habit forming, and Kratom is no exception. Unlike opiates, however, Kratom does not produce a strong addiction, especially at doses generally taken outside South-East Asia. Though a tolerance can easily be built, the body does not seem to crave Kratom, or any of its active alkaloids. After prolonged use, some minor withdrawal symptoms can be noticed such as runny nose, aggression and slight muscle pains.