| Alcohol | Solvent/Preservative | ⚠️ Yes — Alcohol | Ethanol (ethyl alcohol) used as a solvent, preservative, or extraction agent. Present in many liquid formulations. May be relevant for patients avoiding alcohol for medical or religious reasons. |
| Benzoic Acid | Preservative | ⚠️ Yes — Benzoic Acid | A preservative related to sodium benzoate. Same allergy cross-reactivity concerns. |
| Dipropylene Glycol | Solvent/Humectant | ⚠️ Yes — Propylene Glycol | A synthetic glycol used as a solvent and humectant in topical formulations. |
| Peg/ppg-18/18 Dimethicone | Emulsifier/Skin Conditioner | ⚠️ Yes — PEG | A silicone-based emulsifier combining PEG and polypropylene glycol with dimethicone. Used in topical formulations for smooth application. |
| Propylene Glycol | Solvent/Humectant | ⚠️ Yes — Propylene Glycol | An organic compound used as a solvent and humectant. Can cause contact dermatitis in sensitive individuals. |
| Sodium Benzoate | Preservative | ⚠️ Yes — Sodium Benzoate | A food preservative. Can cause urticaria and exacerbate asthma in sensitive individuals. |
| .alpha.-tocopherol Acetate | Antioxidant | No | Vitamin E acetate. Used as an antioxidant to protect active ingredients from degradation during storage. |
| 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. |
| Aluminum Hydroxide | Antacid/Adjuvant | No | An aluminum salt used as an antacid ingredient and as an adjuvant in some vaccine formulations. |
| Ascorbic Acid | Antioxidant | No | Vitamin C. Used as an antioxidant to prevent degradation of active ingredients and as a pH adjuster. |
| Ascorbyl Palmitate | Antioxidant | No | A fat-soluble form of vitamin C used as an antioxidant in pharmaceutical formulations to prevent oxidation of fats and oils. |
| Butylene Glycol | Humectant/Solvent | No | A synthetic glycol used as a humectant and solvent in topical formulations. Helps products spread smoothly on skin. |
| Carbomer Homopolymer | Thickener/Gelling Agent | No | A synthetic acrylic acid polymer used to create gels and thicken topical formulations. |
| Citric Acid Monohydrate | pH Adjuster/Buffer | No | Citric acid in its hydrated form. Used to adjust acidity and as a buffering agent. Derived from citrus fruits or fermentation. |
| Cyclomethicone 5 | Emollient/Carrier | No | A volatile silicone that evaporates quickly, leaving a smooth feel. Used as a carrier and emollient in topical products. |
| Dimethicone 20 | Skin Protectant | No | A silicone-based polymer used as a skin protectant, emollient, and anti-foaming agent in topical formulations. |
| Dipalmitoylphosphatidylglycerol, Dl-? | Surfactant/Stabilizer | No | A synthetic phospholipid used as a lung surfactant component and stabilizer in inhaled formulations. |
| Disodium Citrate Sesquihydrate | Buffer | No | A sodium salt of citric acid used as a buffering agent to maintain pH stability in pharmaceutical solutions. |
| Ethylhexyl Hydroxystearate? | Emollient | No | A synthetic ester used as an emollient and skin-conditioning agent in topical formulations. |
| 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 Isostearate | Emulsifier | No | A glycerin ester used as an emulsifier and skin-conditioning agent in topical formulations. |
| Glyceryl Oleate? | Emulsifier/Emollient | No | A glyceride ester used as an emulsifier, emollient, and skin-conditioning agent in topical formulations. |
| Guinea Green B? | — | No | — |
| Hamamelis Virginiana Top Water | Skin Conditioner | No | Witch hazel distillate, a plant-derived astringent used in topical formulations to soothe and tone the skin. |
| Hexylene Glycol | Solvent/Humectant | No | A synthetic glycol used as a solvent, humectant, and viscosity reducer in topical formulations. |
| Hyaluronate Sodium | Moisturizer/Viscosity Agent | No | Sodium hyaluronic acid. A naturally occurring substance used as a moisturizer and viscosity agent in ophthalmic and topical formulations. |
| Hydroxypropyl Betadex? | — | No | — |
| Isomalt | — | No | — |
| Methyl Laurate | Emollient/Solvent | No | A fatty acid ester used as an emollient and solvent in topical formulations. |
| Pectin? | — | 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. |
| Pineapple | — | No | — |
| Polyethylene Glycol 400 | Solvent/Plasticizer | No | A low-molecular-weight PEG used as a solvent and plasticizer in oral and topical formulations. Rare but documented allergic reactions to PEG compounds. |
| Polysorbate 20 | Emulsifier/Solubilizer | No | A non-ionic surfactant similar to polysorbate 80 but derived from lauric acid. Used to solubilize and stabilize formulations. |
| Potassium Sorbate | Preservative | No | A potassium salt of sorbic acid used to inhibit mold and yeast growth in pharmaceutical formulations. |
| Silica Dimethyl Silylate | — | No | — |
| Sodium Chloride | Tonicity Agent | No | Common table salt. Used to adjust the osmotic pressure of injectable and ophthalmic solutions to match body fluids. |
| Sodium Succinate Hexahydrate? | — | No | — |
| Sorbitan Tristearate? | Emulsifier | No | A non-ionic surfactant (Span 65) used to stabilize water-in-oil emulsions 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. |
| Stearic Acid | Lubricant | No | A fatty acid used as a lubricant in tablet manufacturing. |
| Tocopherol | Antioxidant | No | Natural vitamin E. Used as an antioxidant to protect active ingredients from oxidation and extend product shelf life. |