The Raw Food Family, with almost half a million likes, made this post on June 15, 2014.

FLUORIDE: Did you Know

It claims,

  • In 1955, Crest became the first fluoride toothpaste.
  • Fluoride calcifies the pineal gland, otherwise known as your 3rd eye which literally has rods and cones, just like your other eyes!
  • Fluoride is so toxic that it [sic] considered Hazardous Waste by the EPA.
  • Hitler fluoridated the water in the concentration camps to sedate the prisoners. (FALSE)
  • Fluoride is the same ingredient in rat poison and Prozac
  • According to Dr. Bill Osmunson, there's the same equivalence of fluoride in an 8 ounce glass of fluoridated tap water as there is in a "pea sized" amount needed to call the Poison Control Center, as recommended on the back of any fluoridated toothpaste.

Is there fluoride in rat poison and Prozac?

  • 3
    The claim about Hitler, as least, is a duplicate of skeptics.stackexchange.com/questions/14042/… Mar 9, 2015 at 1:59
  • 2
    @Michael This is a letter claiming to be by Dr. Osmunson. He has also been featured on Mercola's stuff. In the fluoride opposition camp, he's somewhat well known, I think. And here's an interesting study/article he wrote.
    – user11643
    Mar 9, 2015 at 4:47
  • 35
    Looks an awful lot like an appeal to fear. Fluoride is used in dangerous substance X. Hitler put it in drinking water for Jews. Etc etc. Pretty much the same arguments can be applied to any chemical, including water, and actually have been. (See the Dihydrogen Monoxide hoax)
    – GordonM
    Mar 9, 2015 at 13:10
  • 2
    Everything is poisonous given a large enough dose. The practicality of using something like pure H2O as a poison is a different subject matter.
    – MonkeyZeus
    Mar 9, 2015 at 16:37
  • 1
    Ah, mentioning Hitler in your argument, a sure-fire way to show you've made a well-considered case that doesn't rely on hyperbole. Also, see "dihydrogen monoxide hoax" to see why it's pretty much meaningless to say "substance X is an ingredient in dangerous substance Y"
    – GordonM
    Mar 10, 2017 at 16:53

2 Answers 2


"Fluoride" is fluoride-containing compounds, such as sodium fluoride or sodium monofluorophosphate.

Prozac aka the fluoxetine molecule contains fluorine atoms.

The first "rat poison" I thought of was warfarin which doesn't contain fluorine atoms, but looking through a list of other rat poisons there's at least one i.e. fluoroacetamide which does.

Although it's true I think it is a slightly silly statement (perhaps analogous to saying that meat and broccoli contain carbon atoms which are an ingredient of the Ebola virus).

Fluorine is chemically similar to chlorine (i.e. they are both halogens). Chlorine too could be used to make dangerous substances, e.g. poison gas, but it's also a main ingredient of common table salt aka sea salt aka sodium chloride.

One of the comments to/below this answer said that it's important to:

  1. Learn that the dose makes the poison
  2. Have a sense of proportion about the amount of fluorine being talked about

The adage that the dose makes the poison has been known for at least 500 years. People can even die from having too much water, but that fact must not be used as an argument to stop ingesting water.

That adage about 'the dose' happens to be true of an actual "rat poison" too, where for example warfarin (introduced in 1948 as a pesticide against rats and mice) is prescribed medicinally to humans (in carefully administered doses) as an anticoagulant e.g. to treat thrombosis.

That's not to say though "that fluoride is a rat poison" is true. Fluorine is an atom, one the elements, which can be used to make diverse chemical compounds (most of which are not rat poison). It's probably better to view fluoride as a type of salt or mineral. It is true that excessive fluoride is bad for you. This kind of 'excessive' fluoride can occur naturally in some water, or occur as a result of industrial contamination: but the amount of fluoride that's recommended when it's added to drinking water is not 'excessive'.

Fluoride is a component of the human body:

Fluoride anions are found in ivory, bones, teeth, blood, eggs, urine, and hair of organisms. Fluoride anions in very small amounts are essential for humans. There are 0.5 milligrams per liter of fluorine in human blood. Human bones contain 0.2 to 1.2% fluorine. Human tissue contains approximately 50 parts per billion of fluorine. A typical 70-kilogram human contains 3 to 6 grams of fluorine.

Note the quantity that is usually in the human body: i.e. 3 to 6 grams.

The amount of fluorine in fluoridated drinking water is relatively small:

The World Health Organization recommends a guideline maximum fluoride value of 1.5 mg/L as a level at which fluorosis should be minimal.

1.5 mg/L is equivalent to 1.5 g/ton, (i.e. a ton of drinking water to get 1.5 grams of fluorine).

One more comment -- even though original research and theoretical answers are not allowed I hope these (trivial) calculations may be allowed.

Toothpaste typically contains less than 1,500 ppm F (I see mine contains 1,440 ppm).

The Parts-per notation means by weight:

Therefore, it is common to equate 1 gram of water with 1 mL of water. Consequently, ppm corresponds to 1 mg/L

Therefore toothpaste has approximately 1000 times the concentration as the maximum recommended concentration in water (which was quoted as "1.5 mg/L" above).

A "pea-sized" spot of toothpaste might be about 1 cubic centimetre i.e. 1 gram. An "eight-ounce" glass is water is about 200 grams. So the following statement seems to be to be true, within about a factor of 5:

an 8 ounce glass of fluoridated tap water as there is in a "pea sized" amount

(My calculation, which depends on the definition of "pea-sized", was that the toothpaste has about as much fluoride as 5 glasses of water).

What I don't think is true is that these are a poisonous quantity. My fluoridated toothpaste (I'm in France) doesn't mention poison at all. If there's any poison warning label on toothpaste in North America, perhaps that's in case some child sucks down a whole tube of toothpaste as if it's candy.

This Medscape article on Fluoride toxicity says,

In 2011, the American Association of Poison Control Centers reported 20,977 exposures involving toothpaste with fluoride, 18,564 of them in children under the age of 6 years.[3] Only 376 cases were actually treated in the emergency department. Moderate effects were seen in 45 cases, and major effects were seen in one case. No deaths were reported.

Death may result from ingesting as little as 2 g of fluoride in an adult and 16 mg/kg in children. Symptoms may appear with 3-5 mg/kg of fluoride. Estimated toxic dose for fluoride ingestion is 5-10 mg/kg. The estimated lethal dose is 5-10 g (32-64 mg/kg) in adults and 500 mg in small children. One death from ingestion of fluoride toothpaste was reported to the American Association of Poison Control Centers in 2002. No deaths were reported in 2011.

Assuming that any 2-year-old child weighs more than 10 kg, then "Symptoms may appear" with 30 mg fluoride.

If a tube of toothpaste contains 70 ml or 100g of toothpaste, then I think it contains:

  • 1,500 ppm => 1,500 mg/L
  • 100g => 0.1 L
  • therefore 150 mg total per tube.

So (you can double-check my calculation to verify that I haven't dropped a decimal place) a whole tube of toothpaste contains 150 mg which is enough to cause symptoms in a 2-year-old child. "The estimated lethal dose is 500 mg in small children" implies that 4 whole tubes of toothpaste should be lethal in small children. "5-10 g (32-64 mg/kg)" means that the lethal dose for an adult is about 10 times higher than that.

Getting back to the topic (i.e. Prozac), a common dosage for Prozac 20 mg/day. Estimating that a pea-sized spot of toothpaste contains 1.5 mg of fluoride, I think that means that even if fluoride were actually Prozac it isn't concentrated enough in toothpaste, even if you swallow it, for it to have any effect.

  • 4
    Removed a ton of offtopic comments. Write other answers or edit this one folks! Comments are meant for transient information only.
    – Sklivvz
    Mar 9, 2015 at 12:45
  • 1
    Comments are not for extended discussion; this conversation has been moved to chat.
    – Sklivvz
    Mar 9, 2015 at 15:21
  • 2
    @reirab Maybe it depends on the definition of 'bone': does it include water? Does it include marrow? In any case, looking for other references, this suggests 2.5 g in the body, and this suggests 4 g in the body, so they all agree: that the total mass in the body is on the order of a few grams.
    – ChrisW
    Mar 10, 2015 at 18:53
  • 3
    WRT salt, it should be noted that one component of the molecule is an incredibly toxic gas, and the other component explodes violently upon contact with water... Nov 9, 2016 at 12:09
  • 2
    @Shadur And WRT water, it should be noted that the two elements forming it are used as liquid rocket propellants.
    – JAB
    Nov 9, 2016 at 21:34

The "poisonous" aspect has already been addressed, but what about that "pineal gland" claim?

The pineal gland is located in the brain of vertebrates, and regulates sleep patterns through the production of melatonin. As this is related to both daily and seasonal light changes, the gland does act on visual information, but that information comes from the retina, not from itself. The concept of a "third eye" is addressed related to this question.

The pineal gland accumulates both calcium and fluoride, and this accumulation is correlated with age. This process is thought to be related to the hormone changes during sexual development.

This study notes that the process seems to be more related to "constitution" than "environmental factors", since the incidence of calcification seemed to differ with race but not with socioeconomic factors. One would expect a strong correlation with socioeconomic factors if water fluoridation were to blame.

  • 1
    The calcification of the pineal gland probably has to do with the formation of insoluble calcium phosphate, which normally contains hydroxide ions and creates hydroxyapatite. Fluoride ions can displace the hydroxide, forming fluorapatite. So the fluoride ions probably enter the pineal gland after the calcification process has begun, otherwise it wouldn't have a hydroxyapatite substrate to enter. Avoiding fluoride probably doesn't prevent the calcification either.
    – user137
    Mar 10, 2015 at 21:49

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .