Lamar Odom, NBA star and ex-husband of reality TV fixture Khloé Kardashian, was rushed to the hospital yesterday after losing consciousness at a Nevada brothel. Breaking updates indicate he may have suffered from one or more strokes.

According to those at the brothel with him, he had been taking large quantities of “herbal Viagra.” It is also being reported that he was found to have a substantial amount of cocaine in his system, though no illegal drugs were found near him at the time.

It is difficult to know with certainty exactly what was in the supplements Odom was ingesting. Unfortunately, even Odom himself may not have had much idea what it was he was taking so much of. If the reports of cocaine use bear out, the combination may have been deadly.

Unlike prescription medications, herbal supplements are not regulated for safety and efficacy by the Food and Drug Administration (FDA). Despite the assumptions many make about supposedly natural alternatives to pharmaceutical products, they may contain dangerous quantities of the active ingredients found in the plants from which they are derived. Alternatively, they may contain ingredients totally different from what’s on the label, or no active ingredients whatsoever. This year, the Attorney General of New York issued cease and desist letters to several major retailers after DNA analysis showed that supplements being sold supposedly with ingredients like valerian or St. John’s wort instead were either unrecognizable or came from totally different plants.

The Mayo Clinic cautions against taking any kind of herbal supplement for treatment of erectile dysfunction (ED), the condition for which Viagra is prescribed. They warn that while these products may include ingredients that relax the walls of blood vessels in the penis (which is how the pharmaceutical version works), they may not be specific enough in their action, and cause dangerous changes in blood pressure overall.

In March, the FDA warned against taking a supplement simply called Herb Viagra after it was found that it contained sildenafil, the active ingredient in the prescription medication. (Whether or not this was the specific product Odom was taking is unclear.) Those who thought they could avoid the health risks of the medication by taking the herbal alternative instead were getting the exact product they were trying to avoid. Several years ago, the United Kingdom’s equivalent to the FDA issued a similar warning about a Chinese “herbal Viagra” supplement known as Jia Yi Jian, which was found to contain dangerous levels of both the active ingredient in the ED medication Cialis and a different medication used to treat obesity. All of these pharmaceutical adulterants can cause problems with blood pressure, especially in unhealthy doses.

Yet another Chinese herb supposedly helpful for enhancing libido and treating ED is the aptly named horny goat weed, which contains the compound icariin and is available at many supplement stores. As WebMD is all too happy to tout (yet another reason for me to dislike it), icariin may have Viagra-like effects on penile blood flow. Unfortunately, its safety is not established, and it may cause dangerous elevation in blood pressure, especially combined with other herbal ingredients with which it is often paired (PDF).

Elevated blood pressure is also a side effect of cocaine use. If Odom has indeed had a stroke, that may have been the result of an overdose of the drug alone, or a combination of both it and an ingredient in the supplement he was taking. High blood pressure is the most significant risk factor for the kind of stroke he is said to have suffered (the most common variety overall), which is the result of a loss of blood flow to a region of the brain. When blood supply is cut off, usually because of a clot, the area no longer receiving oxygen can be severely damaged.

Given that Odom was at a brothel when he lost consciousness, it may seem intuitive to add sexual activity to the list of risk factors that contributed to his health crisis. However, while sex does raise blood pressure, it only does so briefly and not to dangerous levels. The stroke he suffered is much more likely to have been triggered by the blood pressure effects of one or more of the substances he was taking.

The prognosis for strokes is generally better for younger patients and those whose health was good prior to the stroke. Beyond broad statements like that, however, I can’t pronounce with any authority about his long-term recovery should he make it through his current period of critical peril. (I am neither a neurologist nor in any way connected to his care.) He will certainly require therapies to help him regain the functioning that may have been lost as a result of damage to his brain. Sadly, it is a relatively safe prediction to make to say his return to the NBA is unlikely.