PFAS Chemicals

PFAS, short for per- and polyfluoroalkyl substances, are synthetic chemicals used in nonstick coatings, stain and water repellents, food packaging, and firefighting foam. They resist breaking down, which is why they are nicknamed forever chemicals.

This panel does not diagnose a disease. It estimates your body's internal load of these chemicals, tells you which ones are present, and lets you compare yourself against the general population. That is the first honest step toward reducing exposure.

What This Panel Reveals

Blood is the standard material scientists use to gauge how much PFAS a person has absorbed over time. The reason is simple: many of these chemicals bind to proteins in your blood and stay there for years, so a single draw captures accumulated exposure rather than a one-day snapshot.

The panel covers three overlapping stories. The first is your legacy burden, from the older, long-lasting compounds like PFOA, PFOS, PFNA, and PFHxS that are detectable in more than 96% of people tested in United States surveys. The second is your recent exposure, seen in short-lived compounds that clear in weeks and therefore point to something you are encountering now. The third is your emerging-chemistry exposure, from newer replacement compounds such as GenX that tend to show up in people living near contaminated water or industrial sources.

A handful of the items on your report are not chemicals from your body at all. They are carbon-13 labeled reference compounds (called internal standards) that the laboratory adds to your sample. Their only job is to make the real measurements accurate by tracking how the machine handles each chemical, so your PFOA and PFOS numbers can be trusted.

How to Read Your Results Together

No single PFAS tells the whole story, which is the entire point of measuring many at once. The pattern across compounds hints at when and how you were exposed. Long-lasting compounds reflect years of accumulation, while short-lived ones reflect something current.

Half-life explains these patterns. Human studies estimate that PFOA takes roughly 1.5 to 5 years to fall by half after exposure stops, PFOS about 3 to 6 years, and PFHxS often the longest at 3 to more than 8 years. By contrast, a short-chain compound like PFBS clears with an average half-life near 44 days. One chlorinated replacement compound is the exception, with a median total elimination half-life estimated at 15.3 years, longer than any other PFAS reported in people.

What to Do with Your Results

There is no medicine that reliably clears PFAS from your body, so the practical response is to find and cut off sources. The National Academies of Sciences, Engineering, and Medicine (a group that advises United States health agencies) suggests that people with a combined PFAS level above 20 nanograms per milliliter get extra attention at check-ups, including a cholesterol panel, because higher exposure has been linked to changes in blood lipids. This threshold is not universally endorsed, and some medical groups note that no clinical cutoff for PFAS testing is firmly established, so treat it as a prompt for closer follow-up rather than a hard line.

Human studies tie several of these compounds to measurable body changes. In one prediabetic adult cohort, each doubling of PFOA was associated with higher total cholesterol at baseline (6.1 mg/dL, 95% CI: 3.1 to 9.0). Other studies link the short-chain compounds PFBA and PFHxA to higher levels of a liver enzyme called gamma-glutamyl transferase, and reduced antibody response to vaccines is one of the better-supported effects of PFAS exposure. These are population-level associations, not a personal prediction that you will become ill.

Companion tests sharpen the picture. A cholesterol panel, liver enzymes, thyroid tests, and a kidney marker can show whether your body is showing any of the changes associated with PFAS. If your levels are high, testing your drinking water and reviewing occupational or product sources is the most direct action. Because these chemicals leave slowly, retesting once a year is enough to confirm that your numbers are trending down after you change your environment.

When Results Can Be Misleading

A blood level shows exposure, not the source or the timing. For long-lasting compounds, your number may reflect exposure from years ago rather than your current water. Levels also differ by age and sex, tend to rise with age, and are often higher in men, so your result is best read against a reference population rather than in isolation.

The panel is also incomplete by design. Some newer, water-mobile PFAS are frequently found in drinking water yet barely register in blood, so a clean serum result does not rule out exposure to every PFAS. Environmental testing may be needed alongside your blood work.