What's inside the medicine cabinet?
Read the labels on Tylenol, Advil, NyQuil and Vicks VapoRub, and meet the molecule behind each active ingredient they list, with the strength each label states.
What the marks and numbers mean
- Added by the maker
- Put in by whoever makes the product; an ingredient on a label is marked this way.
- Calculated
- Worked out from the structure (molecular weight, by PubChem).
1. The pain reliever Tylenol and NyQuil share: acetaminophen
Acetaminophen
C8H9NO2The pain and fever reliever sold as Tylenol and Panadol, called paracetamol outside the US. More than a century after it was first made, how it eases pain is still not fully understood.
- Tylenol Extra StrengthPain reliever/fever reducer500 mg
- Vicks NyQuil Intense Flu LiquiCapsPain reliever/fever reducer500 mg
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Acetaminophen, sold as Tylenol or paracetamol, eases pain and fever without the stomach irritation of the NSAIDs.
Acetaminophen, called paracetamol outside the US, acts mainly in the central nervous system and does very little for inflammation, which is why a sprain and a headache are not the same problem for it.
Sources and notes
- The drawingscomputedPubChem structures, drawn by RDKit
- The line on Acetaminophenfrom sourceMoleculeFinder curated
- Acetaminophen: added by the makerfrom sourceMoleculeFinder curatedOn the Tylenol Extra Strength label; an ingredient a label lists is added by the maker.
- Tylenol Extra Strength labelfrom sourceDailyMedListed as ACETAMINOPHEN; the purpose and strength as the label states them.
- Vicks NyQuil Intense Flu LiquiCaps labelfrom sourceDailyMedListed as ACETAMINOPHEN; the purpose and strength as the label states them.
- More on Acetaminophenfrom sourceMoleculeFinder curated
- The Acetaminophen vs Ibuprofen comparisonfrom sourceMoleculeFinder comparison notes
- Acetaminophen: molecular weightcomputedPubChem
2. Advil's ibuprofen, which eases inflammation too
Ibuprofen
C13H18O2The anti-inflammatory painkiller sold as Advil and Motrin. It is sold as a mirror-image pair, and the body turns much of the inactive form into the active one.
- AdvilPain reliever/Fever reducer200 mg
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Ibuprofen is an NSAID: it blocks the COX enzymes throughout the body, which is why it reduces inflammation and swelling as well as pain.
Ibuprofen is the everyday anti-inflammatory, blocking the COX enzymes that build the prostaglandins behind pain, fever, and swelling.
Sources and notes
- The drawingscomputedPubChem structures, drawn by RDKit
- The line on Ibuprofenfrom sourceMoleculeFinder curated
- Ibuprofen: added by the makerfrom sourceMoleculeFinder curatedOn the Advil label; an ingredient a label lists is added by the maker.
- Advil labelfrom sourceDailyMedListed as IBUPROFEN; the purpose and strength as the label states them.
- The Acetaminophen vs Ibuprofen comparisonfrom sourceMoleculeFinder comparison notes
- More on Ibuprofenfrom sourceMoleculeFinder curated
- Ibuprofen: molecular weightcomputedPubChem
3. The DM on the box: dextromethorphan
Dextromethorphan
C18H25NOThe cough suppressant marked DM on cold medicine boxes, related to morphine in structure but not in its effect on pain.
- Vicks NyQuil Intense Flu LiquiCapsCough suppressant15 mg
- Vicks DayQuil Severe Cold and FluCough suppressant10 mg
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Sources and notes
- The drawingscomputedPubChem structures, drawn by RDKit
- The line on Dextromethorphanfrom sourceMoleculeFinder curated
- Dextromethorphan: added by the makerfrom sourceMoleculeFinder curatedOn the Vicks NyQuil Intense Flu LiquiCaps label; an ingredient a label lists is added by the maker.
- Vicks NyQuil Intense Flu LiquiCaps labelfrom sourceDailyMedListed as DEXTROMETHORPHAN HYDROBROMIDE; the purpose and strength as the label states them.
- Vicks DayQuil Severe Cold and Flu labelfrom sourceDailyMedListed as DEXTROMETHORPHAN HYDROBROMIDE; the purpose and strength as the label states them.
- Dextromethorphan: molecular weightcomputedPubChem
4. In NyQuil, not in DayQuil: doxylamine
Doxylamine
C17H22N2OA sedating antihistamine used as an over-the-counter sleep aid and, combined with vitamin B6, for nausea in pregnancy.
- Vicks NyQuil Intense Flu LiquiCapsAntihistamine6.25 mg
- Unisom SleepTabsNighttime sleep-aid25 mg
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Sources and notes
- The drawingscomputedPubChem structures, drawn by RDKit
- The line on Doxylaminefrom sourceMoleculeFinder curated
- Doxylamine: added by the makerfrom sourceMoleculeFinder curatedOn the Vicks NyQuil Intense Flu LiquiCaps label; an ingredient a label lists is added by the maker.
- Vicks NyQuil Intense Flu LiquiCaps labelfrom sourceDailyMedListed as DOXYLAMINE SUCCINATE; the purpose and strength as the label states them.
- Unisom SleepTabs labelfrom sourceDailyMedListed as DOXYLAMINE SUCCINATE; the purpose and strength as the label states them.
- Doxylamine: molecular weightcomputedPubChem
5. The cool and the warm in Vicks VapoRub: menthol and camphor
The cold feeling of peppermint, chewing gum, and cough drops. It does not lower the temperature, it opens the same nerve channel that real cold does.
The penetrating smell of Vicks VapoRub and mothballs, tapped from the camphor laurel tree and now mostly made from turpentine.
- Vicks VapoRubCamphorCough suppressant & topical analgesic4.8%
- Vicks VapoRubMentholCough suppressant & topical analgesic2.6%
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Menthol activates TRPM8, the cold receptor, which is why it feels cool without lowering any temperature, and it is the reason peppermint and menthol cigarettes feel the way they do. Camphor is less selective, working on several TRP channels including the warm ones, which is why it reads as both cooling and warming and why it appears in chest rubs alongside menthol rather than instead of it.
Sources and notes
- The line on Mentholfrom sourceMoleculeFinder curated
- The line on Camphorfrom sourceMoleculeFinder curated
- The drawingscomputedPubChem structures, drawn by RDKit
- Menthol: added by the makerfrom sourceMoleculeFinder curatedOn the Vicks VapoRub label; an ingredient a label lists is added by the maker.
- Camphor: added by the makerfrom sourceMoleculeFinder curatedOn the Vicks VapoRub label; an ingredient a label lists is added by the maker.
- Vicks VapoRub labelfrom sourceDailyMedListed as CAMPHOR (SYNTHETIC); the purpose and strength as the label states them.
- Vicks VapoRub labelfrom sourceDailyMedListed as MENTHOL; the purpose and strength as the label states them.
- The Menthol vs Camphor comparisonfrom sourceMoleculeFinder comparison notes
Also on the list
Read more
- Naproxen. A longer-acting anti-inflammatory painkiller sold as Aleve, used for pain, fever, and inflammation.
- Phenylephrine. The decongestant that replaced pseudoephedrine on open pharmacy shelves, and the one US regulators concluded does not work when swallowed.
- Guaifenesin. The expectorant in Mucinex and many cough syrups, taken to loosen chest congestion.
Sources and notes
- The line on Naproxenfrom sourceMoleculeFinder curated
- The line on Phenylephrinefrom sourceMoleculeFinder curated
- The line on Guaifenesinfrom sourceMoleculeFinder curated
- The drawingscomputedPubChem structures, drawn by RDKit
- Naproxen: added by the makerfrom sourceMoleculeFinder curatedOn the Aleve label; an ingredient a label lists is added by the maker.
- Phenylephrine: added by the makerfrom sourceMoleculeFinder curatedOn the Vicks DayQuil Severe Cold and Flu label; an ingredient a label lists is added by the maker.
- Guaifenesin: added by the makerfrom sourceMoleculeFinder curatedOn the Vicks DayQuil Severe Cold and Flu label; an ingredient a label lists is added by the maker.
Where next?
Advil's active ingredient is ibuprofen and Tylenol Extra Strength's is acetaminophen; both labels list cellulose, starch and shellac as inactive ingredients.
Ibuprofen is an NSAID that eases inflammation as well as pain, while acetaminophen acts mainly in the central nervous system and does little for inflammation.