| Cetyl Alcohol | Emulsifier/Thickener | ⚠️ Yes — Cetyl Alcohol | A fatty alcohol used in topical formulations. Can cause contact dermatitis. |
| Propylene Glycol? | Solvent/Humectant | ?Uncertain — Propylene Glycol | An organic compound used as a solvent and humectant. Can cause contact dermatitis in sensitive individuals. |
| Stearyl Alcohol | Emulsifier/Thickener | ⚠️ Yes — Stearyl Alcohol | A fatty alcohol used in creams and ointments. Can cause contact dermatitis. |
| 1,2,6-hexanetriol? | Humectant/Plasticizer | No | A synthetic triol used as a humectant and plasticizer in topical and transdermal formulations. |
| Acacia | Emulsifier/Binder | No | Gum arabic. A natural gum from the acacia tree used as an emulsifier, binder, and suspending agent in pharmaceutical formulations. |
| Acrylic Acid-2-ethylhexyl Acrylate-2-hydroxyethyl Acrylate-vinyl Acetate Copolymer (for Duro-tak 87-2070)? | Adhesive | No | A pressure-sensitive adhesive polymer used in transdermal patches to hold the patch to the skin. |
| Arginine | — | No | — |
| Butylated Hydroxytoluene? | Antioxidant | No | BHT. A synthetic antioxidant used to prevent oxidative degradation of fats and oils in pharmaceutical products. Rare contact sensitivity reported. |
| Butylene Glycol | Humectant/Solvent | No | A synthetic glycol used as a humectant and solvent in topical formulations. Helps products spread smoothly on skin. |
| Docosanol | Antiviral/Emollient | No | A fatty alcohol used as the active ingredient in cold sore treatments and as an emollient in topical formulations. |
| Edetate Sodium | Chelating Agent | No | A sodium salt of EDTA used to bind metal ions, preventing degradation of active ingredients and preserving formulation stability. |
| Gluceptate Sodium | — | No | — |
| Glycerin | Humectant/Solvent | No | A sugar alcohol that attracts moisture. Used as a humectant, solvent, and sweetener in many oral and topical medications. Generally well tolerated. |
| Glyceryl Monocaprylate | Penetration Enhancer/Emulsifier | No | A glyceride ester used to enhance skin penetration and as an emulsifier in topical formulations. |
| Glyceryl Monostearate | Emulsifier | No | An emulsifier that helps oil and water mix in creams and ointments. Derived from glycerin and stearic acid. |
| Hamamelis Virginiana Top Water | Skin Conditioner | No | Witch hazel distillate, a plant-derived astringent used in topical formulations to soothe and tone the skin. |
| Hypromellose Acetate Succinate, Unspecified? | Enteric Coating | No | A cellulose derivative that dissolves at higher pH, used as an enteric coating to protect drugs from stomach acid. Plant-derived. |
| Lanolin Oil? | Emollient | No | An oil derived from sheep wool (lanolin). Used as an emollient and skin conditioner. Animal-derived — relevant for vegan patients. Can cause contact dermatitis in lanolin-sensitive individuals. |
| Limonene, (+)- | Fragrance/Solvent | No | A citrus-derived terpene used as a fragrance component and solvent. Can cause contact sensitization in some individuals. |
| Methyl Salicylate? | Flavoring/Counterirritant | No | Oil of wintergreen. Used as a flavoring agent and topical counterirritant (creates a warming sensation). Can cause sensitivity in aspirin-intolerant individuals. |
| Myristyl Alcohol | — | No | — |
| Palmitic Acid | — | No | — |
| Phenoxyethanol | Preservative | No | A synthetic preservative used to prevent microbial growth in topical and some oral formulations. Can cause skin irritation in sensitive individuals. |
| Potassium Metaphosphate | Buffer/Stabilizer | No | A potassium phosphate salt used as a buffering agent and stabilizer in pharmaceutical formulations. |
| Pullulan | — | No | — |
| Silicon Dioxide | Glidant | No | A mineral (silica) used to improve powder flow during tablet manufacturing. Also called colloidal silicon dioxide. |
| Sodium Pyrrolidone Carboxylate | Humectant | No | Sodium PCA. A natural moisturizing factor component used as a humectant in topical formulations. |
| Soybean Lecithin | Emulsifier | No | A phospholipid mixture extracted from soybeans, used as an emulsifier and wetting agent. Derived from soy — must be avoided by individuals with soy allergy. |
| Squalane | Emollient | No | A saturated hydrocarbon used as an emollient and moisturizer. Originally from shark liver oil, now commonly plant-derived (olive or sugarcane). |
| Stearic Acid | Lubricant | No | A fatty acid used as a lubricant in tablet manufacturing. |
| Xanthan Gum | Thickener/Stabilizer | No | A polysaccharide produced by bacterial fermentation, used to thicken and stabilize liquid and semi-solid formulations. Derived from corn sugar fermentation — may be relevant for corn-sensitive individuals. |