Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ALA-CORT vs ALA-SCALP
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Topical corticosteroid that induces phospholipase A2 inhibitory proteins, collectively called lipocortins, which inhibit the release of arachidonic acid, thereby reducing prostaglandin and leukotriene synthesis, and exerting anti-inflammatory, antipruritic, and vasoconstrictive effects.
ALA-SCALP (aminolevulinic acid) is a photosensitizer precursor that is converted intracellularly to protoporphyrin IX (Pp IX), which accumulates in cells with increased heme synthesis, such as rapidly dividing cells. Upon exposure to blue light (BLU-U®), Pp IX produces reactive oxygen species, leading to cellular damage and apoptosis of targeted cells.
Relief of inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses (FDA),Off-label: Atopic dermatitis, psoriasis, contact dermatitis, lichen planus, discoid lupus erythematosus
Treatment of minimally to moderately thick actinic keratoses of the scalp (Grade 1 or 2) in immunocompetent patients,Off-label: other photosensitivity disorders
Topical: Apply a thin film to affected area 3-4 times daily. Dosage strength: 0.5% cream or ointment.
Topical application of a 5% solution to the scalp twice daily.
Terminal elimination half-life: 1–2 hours for hydrocortisone (active component), prolonged in liver disease or with concurrent CYP3A4 inhibitors.
Not applicable; topical ALA-SCALP is not significantly absorbed systemically. After systemic absorption from photodynamic therapy, terminal half-life is approximately 1 hour due to rapid metabolism.
Topically applied; systemic absorption is minimal but can be increased with use on large areas, occlusive dressings, or damaged skin. Absorbed portion is metabolized primarily in the liver via hepatic microsomal enzymes (CYP3A4) and excreted by the kidneys.
ALA is metabolized intracellularly via the heme biosynthesis pathway to protoporphyrin IX (Pp IX).
Primarily hepatic metabolism (approximately 95%) followed by renal excretion of inactive metabolites (<5% unchanged). Biliary/fecal excretion is negligible.
Primarily renal elimination of metabolites; <1% excreted unchanged in urine. Biliary/fecal excretion is negligible.
Hydrocortisone is approximately 90–95% bound to corticosteroid-binding globulin (CBG, transcortin) and albumin.
Not characterized; systemic levels are negligible after topical administration.
Apparent volume of distribution (Vd) is approximately 0.4–0.6 L/kg, indicating moderate tissue distribution and limited penetration into CNS.
Not applicable for topical route. If systemic exposure occurs, Vd is approximately 0.5 L/kg, consistent with distribution into total body water.
Topical: Bioavailability is negligible (<1%) through intact skin; may increase (up to 30%) with damaged skin or occlusive dressings. Rectal: Bioavailability is approximately 10–20% via mucosal absorption, with first-pass metabolism reducing systemic exposure.
Topical: Systemic bioavailability is minimal (<1%) due to poor percutaneous absorption and rapid local metabolism.
No adjustment required for topical use; systemic absorption minimal.
No dose adjustment required for renal impairment.
No adjustment required for topical use; hepatic metabolism negligible.
No dose adjustment required for hepatic impairment.
Children ≥2 years: Apply a thin film to affected area 2-3 times daily. Use lowest potency preparation; avoid prolonged use.
Safety and efficacy in pediatric patients have not been established.
Use lowest effective dose; monitor for skin atrophy and systemic effects due to thinner skin and increased percutaneous absorption.
No specific dose adjustment recommended; use with caution due to potential increased sensitivity.
None
No FDA black box warning.
Systemic absorption may cause reversible HPA axis suppression,Cushing's syndrome, hyperglycemia, and glucosuria with prolonged use,Local adverse reactions: atrophy, striae, telangiectasias, acneiform eruptions, perioral dermatitis,May mask signs of infection,Use with caution in pediatric patients due to increased susceptibility to HPA axis suppression,Avoid use on face, intertriginous areas, and under occlusive dressings unless directed by physician
Photosensitivity: avoid exposure to sunlight or bright indoor light (e.g., examination lamps, operating room lamps) for at least 40 hours post-application.,Application site reactions: severe stinging, burning, erythema, and edema may occur.,Use sun-protective measures (e.g., wide-brimmed hat, sunscreen) after treatment.,Do not apply to eyes or mucous membranes.
Hypersensitivity to any component of the formulation,Untreated bacterial, viral, fungal, or parasitic skin infections,Viral skin infections (e.g., herpes simplex, varicella) at treatment site,Perioral dermatitis,Rosacea
Hypersensitivity to aminolevulinic acid or any component of the formulation,Cutaneous photosensitivity at wavelengths of 400-450 nm,Porphyria
No known food interactions with topical ALA-CORT.
No known food interactions. No dietary restrictions required.
FDA Pregnancy Category C. First trimester: No adequate human studies; animal studies show increased risk of cleft palate. Second/third trimester: Risk of intrauterine growth restriction, adrenal suppression in fetus. Avoid prolonged use.
No evidence of teratogenicity; topical application with minimal systemic absorption. First trimester: unlikely risk. Second/third trimester: no known fetal risks from maternal use.
Provides small amounts in breast milk; M/P ratio unknown. At maternal doses up to 80 mg/day, no adverse effects reported in infants. Consider risk-benefit with high doses or prolonged therapy.
Minimal systemic absorption; unlikely to appear in breast milk. M/P ratio not established. Considered compatible with breastfeeding.
Pregnancy-induced pharmacokinetic changes (increased clearance, volume of distribution) may require increased dosing, but clinical response should guide adjustment. Avoid high doses and prolonged use.
No dosage adjustment required; pharmacokinetics unlikely altered due to topical route.
ALA-CORT (hydrocortisone acetate 2.5% and pramoxine HCl 1%) is a topical corticosteroid with anesthetic. Use for short-term relief of pruritus and inflammation in corticosteroid-responsive dermatoses. Avoid prolonged use on intertriginous or occluded areas. Limit to <2 weeks continuous use in adults to avoid skin atrophy. Not recommended for children <2 years.
ALA-SCALP is a topical aminolevulinic acid preparation used for photodynamic therapy of actinic keratoses on the scalp. Must be applied by a healthcare professional. Avoid sun exposure to treated area for 48 hours post-application due to photosensitivity. Do not apply to eyes or mucous membranes. Lesions should be prepped by gentle removal of scales and crusts. Use with a compatible light source (blue light). Burning and stinging during light exposure is common; consider pain management strategies.
Apply a thin layer to affected area no more than 3-4 times daily.,Do not cover with bandages or plastic unless directed by doctor.,Avoid contact with eyes, mouth, or broken skin.,Discontinue and notify doctor if infection, irritation, or no improvement after 7 days.,Do not use for diaper dermatitis or under diapers/occlusive dressings.,Keep out of reach of children.
This medication is applied by your doctor to treat precancerous spots on your scalp.,After application, you will need a special light treatment (photodynamic therapy).,Avoid sunlight and bright indoor light on the treated area for 48 hours after the procedure.,You may experience temporary redness, swelling, scaling, or discomfort at the treatment site.,Use sunscreen and protective clothing when going outdoors during the photosensitivity period.,Do not wash the treated area for at least 4 hours after the solution is applied.,Contact your doctor if you experience severe pain, blistering, or signs of infection.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ALA-CORT vs ALA-SCALP, answered by our medical review team.
ALA-CORT is a Topical Corticosteroid that works by Topical corticosteroid that induces phospholipase A2 inhibitory proteins, collectively called lipocortins, which inhibit the release of arachidonic acid, thereby reducing prostaglandin and leukotriene synthesis, and exerting anti-inflammatory, antipruritic, and vasoconstrictive effects.. ALA-SCALP is a Topical Corticosteroid that works by ALA-SCALP (aminolevulinic acid) is a photosensitizer precursor that is converted intracellularly to protoporphyrin IX (Pp IX), which accumulates in cells with increased heme synthesis, such as rapidly dividing cells. Upon exposure to blue light (BLU-U®), Pp IX produces reactive oxygen species, leading to cellular damage and apoptosis of targeted cells.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ALA-CORT and ALA-SCALP depend on the specific clinical indication. These are both Topical Corticosteroid agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ALA-CORT is: Topical: Apply a thin film to affected area 3-4 times daily. Dosage strength: 0.5% cream or ointment.. The standard adult dose of ALA-SCALP is: Topical application of a 5% solution to the scalp twice daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ALA-CORT and ALA-SCALP in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ALA-CORT is classified as Category C. FDA Pregnancy Category C. First trimester: No adequate human studies; animal studies show increased risk of cleft palate. Second/third trimester: Risk of intrauterine growth restri. ALA-SCALP is classified as Category C. No evidence of teratogenicity; topical application with minimal systemic absorption. First trimester: unlikely risk. Second/third trimester: no known fetal risks from maternal use.. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.