Get a Free 5ml Mini Now Free 5ml Mini With Every Order of The Mantle
Moumoujus

ACETAMINOPHEN.

Questionable CAS 103-90-2 / SKIN CONDITIONING

Acetaminophen, widely recognized as an oral analgesic and antipyretic, presents intriguing potential for topical application. Research indicates its experimental use in addressing localized itch, suggesting specific dermal mechanisms for its antipruritic effects, though it is not a conventional cosmetic ingredient.

Summary

Antipruritic Masking

Science

Mechanism of Action

Topically, acetaminophen is thought to reduce itch by inhibiting prostaglandins that contribute to pruritic sensations. Its metabolites may also interact with and sensitize transient receptor potential vanilloid 1 (TRPV1) receptors, which are known mediators in both itch transmission and inflammatory processes within the skin.

Research

Clinical Evidence

Medium confidence
Effective range 0.1–5%
Optimal

N/A

Key findings

  1. 01 In double-blind, vehicle-controlled pilot studies involving healthy volunteers, topical acetaminophen gels at concentrations of 2.5% and 5% significantly reduced the intensity and duration of both histamine and cowhage-induced itch. These formulations demonstrated rapid skin penetration, with no observed adverse effects or alterations to heat pain thresholds.
  2. 02 A 1% topical acetaminophen concentration did not yield a statistically significant reduction in itch intensity when compared to a vehicle gel.

Transparency

Dusting Analysis

Not commonly dusted

Acetaminophen is primarily an active pharmaceutical ingredient used internally for pain and fever, and it is not commonly found in cosmetic skincare products. If included in a cosmetic, its concentration would need to be within the 2.5-5% range to demonstrate the antipruritic efficacy observed in experimental studies. Use at sub-efficacious concentrations would constitute 'dusting' for marketing purposes, while use at effective concentrations for therapeutic claims would classify the product as an over-the-counter drug.

The Formula

Formulation

Solubility
Water
Optimal pH 5.5 – 6.5
0 7 14

Stability

Acetaminophen's solubility in water is slight at cold temperatures but significantly increases with heat. It is freely soluble in alcohol and various organic solvents. Optimal stability for aqueous solutions is maintained within a pH range of 5.5-6.5, though it can undergo decomposition when exposed to strong alkalies.

Conflicts

  • strong alkalies

Safety

Safety Profile

CIR Status
Not reviewed
Sensitization risk High

The Cosmetic Ingredient Review (CIR) has not specifically evaluated acetaminophen for its use as a cosmetic ingredient. The FDA has issued warnings regarding rare but serious and potentially fatal skin reactions, including Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP), associated with acetaminophen use (primarily systemic). Individuals who have experienced such reactions are advised to avoid future use. In 2024, the FDA proposed mandating warnings about these severe skin reactions on over-the-counter acetaminophen product labels.

Your Skin

Skin Compatibility

No Normal
No Dry
No Oily
No Sensitive
Irritancy Unknown
Comedogenicity Unknown

Our Assessment

Verdict

Questionable

While experimental studies demonstrate promising antipruritic efficacy for topical acetaminophen at concentrations of 2.5-5%, the absence of a dedicated cosmetic safety review and the FDA's warnings regarding severe, rare skin reactions associated with its general use make its inclusion in precision skincare formulations highly questionable.

Related

Similar Ingredients

Finding similar ingredients…