Hydrocortisone
Is It Right for You?
A complete guide to Hydrocortisone — what it treats, how it works, dosages, side effects, and when a clinician may prescribe it following an online consultation.
What Is Hydrocortisone?
Hydrocortisone is the synthetic form of cortisol — the body's primary natural glucocorticoid hormone — produced by the adrenal cortex. It is used across a wide range of clinical contexts as an anti-inflammatory and immunosuppressive agent, and critically, as hormone replacement therapy in conditions where the body is unable to produce adequate cortisol.
Hydrocortisone is unique among corticosteroids in that it closely mirrors the activity and potency of endogenous cortisol. It has both glucocorticoid (anti-inflammatory, metabolic) and mineralocorticoid (sodium and water retention) properties, making it suitable for physiological replacement therapy in adrenal insufficiency. By contrast, more potent synthetic corticosteroids such as prednisolone or dexamethasone are preferred for anti-inflammatory use due to their superior glucocorticoid potency and minimal mineralocorticoid effects.
Hydrocortisone is available in multiple formulations: oral tablets (for systemic use), topical creams and ointments (for skin conditions), rectal foams and suppositories (for inflammatory bowel disease), ear and eye drops, and injectable preparations (for emergency use and perioperative cover). It is suitable for adults and children.
Prescription-strength hydrocortisone in any systemic or injectable form is a prescription-only medication in the UK. A licensed clinician must assess your clinical need before prescribing — which can now be done quickly and conveniently through a telehealth consultation.
What Conditions Is Hydrocortisone Used For?
Hydrocortisone is prescribed across multiple therapeutic areas:
lifelong replacement of cortisol deficiency.
caused by pituitary disorders or long-term corticosteroid use.
to suppress excessive adrenal androgen production while replacing cortisol.
emergency intravenous/intramuscular hydrocortisone for acute life-threatening adrenal insufficiency.
eczema, contact dermatitis, seborrhoeic dermatitis (topical formulations).
ulcerative colitis (rectal hydrocortisone foam or suppositories).
Over-the-counter topical hydrocortisone 1% cream is a mild-potency corticosteroid suitable for short-term use on mild eczema or contact dermatitis. It should not be used on the face for extended periods, near the eyes, on broken skin, or under occlusion without medical advice. Stronger topical steroids require prescription and careful clinical supervision.
How Does Hydrocortisone Work?
Hydrocortisone binds to intracellular glucocorticoid receptors (GRs) found in virtually all cells of the body. The hydrocortisone-GR complex translocates into the cell nucleus, where it acts as a transcription factor — binding to glucocorticoid response elements (GREs) in the promoter regions of target genes and modulating their expression.
Anti-inflammatory effects — Hydrocortisone suppresses the production of pro-inflammatory cytokines (including IL-1, IL-6, TNF-alpha), inhibits phospholipase A2 (reducing arachidonic acid availability and downstream prostaglandin and leukotriene production), decreases the expression of COX-2, and reduces the recruitment and activity of inflammatory cells such as eosinophils, neutrophils, and macrophages.
Immunosuppressive effects — Hydrocortisone reduces lymphocyte proliferation and function, suppresses T-cell activity, and diminishes the immune response — used therapeutically in autoimmune and inflammatory conditions.
Physiological (replacement) effects — In the context of adrenal insufficiency, hydrocortisone restores glucocorticoid activity, regulating glucose metabolism, blood pressure maintenance (potentiating vasopressors), protein catabolism, and the stress response.
Hydrocortisone also has significant mineralocorticoid activity — binding to mineralocorticoid receptors and promoting renal sodium retention and potassium excretion — which is desirable in adrenal replacement but is a limitation in anti-inflammatory use (where more selective glucocorticoids are preferred).
Dosages & Administration
The correct dose depends on the type and severity of infection, age, weight, and kidney function. Always follow your clinician's instructions. The table below is for general reference only.
Administration Tips
For adrenal replacement therapy, take the largest portion of the daily dose in the morning (on waking) to mimic the natural diurnal cortisol peak. A smaller afternoon or early evening dose follows — avoid late evening dosing, as this can cause insomnia.
Always carry a steroid emergency card and an emergency injection kit if you have adrenal insufficiency. Your clinician will provide guidance on sick day rules — when to double or triple your dose.
For topical formulations, apply a thin layer to affected skin only and avoid prolonged use, particularly on the face, in skin folds, or under occlusion, to minimise the risk of skin thinning.
Never stop systemic hydrocortisone abruptly if you have been taking it for more than a few weeks — adrenal suppression from exogenous corticosteroids requires gradual dose tapering under clinician guidance.
Side Effects of Hydrocortisone
Side effects are closely related to dose, duration, and route of administration. Topical hydrocortisone at standard doses carries far fewer systemic risks than oral or injectable forms. Long-term systemic use carries significant risk.
- Weight gain and fluid retention
- Increased appetite
- Insomnia (particularly if taken late in the day)
- Mood changes (euphoria, anxiety, irritability)
- Elevated blood glucose
- Increased susceptibility to infection
- Skin bruising and thinning
- Adrenal suppression and adrenal crisis — if systemic hydrocortisone is stopped abruptly after prolonged use, the suppressed adrenal glands cannot respond to stress, potentially causing a life-threatening adrenal crisis
- Cushing's syndrome — features of cortisol excess with long-term high doses: central obesity, moon face, buffalo hump, striae, hypertension
- Avascular necrosis (osteonecrosis) — particularly of the femoral head; severe hip or joint pain
- Peptic ulceration and gastrointestinal perforation — particularly with concurrent NSAID use
- Severe infection — masked symptoms and impaired immune response
- Osteoporosis and fractures — with prolonged systemic use
- Glaucoma and cataracts — with prolonged use
Patients with adrenal insufficiency who take hydrocortisone as hormone replacement must follow sick day rules: during any significant illness (fever, vomiting, surgery, dental procedures, or major injury), the hydrocortisone dose must be doubled or tripled immediately, and injectable hydrocortisone must be given if oral medication cannot be taken. Failure to increase the dose during stress can cause an adrenal crisis — a life-threatening emergency. All patients should carry a steroid emergency card and know how to administer emergency hydrocortisone.
Drug Interactions
Always disclose all medications and supplements to your clinician or pharmacist before starting hydrocortisone.
Concurrent use significantly increases the risk of gastrointestinal ulceration and bleeding.
Systemic corticosteroids at immunosuppressive doses contraindicate live vaccines due to risk of disseminated infection.
Hydrocortisone raises blood glucose; diabetic patients require increased monitoring and possible dose adjustment of antidiabetic medication.
Hydrocortisone's mineralocorticoid activity causes sodium retention and hypokalaemia, counteracting antihypertensive therapy and worsening hypokalaemia from diuretics.
Important Warnings
Patients with adrenal insufficiency are dependent on hydrocortisone for survival. During significant illness, injury, or surgery, requirements increase dramatically. Failure to increase the dose leads to adrenal crisis — characterised by severe hypotension, vomiting, confusion, and collapse. All patients must carry an emergency steroid card, wear a medical alert bracelet, and have access to injectable hydrocortisone for emergencies.
Prolonged systemic hydrocortisone suppresses the hypothalamic-pituitary-adrenal axis. Abrupt cessation causes acute adrenal insufficiency. Doses must always be tapered gradually under clinical supervision.
Systemic hydrocortisone suppresses the immune system and can mask the signs of infection. Seek prompt medical attention for any unexplained fever or symptoms of infection during treatment.
Hydrocortisone replacement therapy is essential for patients with adrenal insufficiency during pregnancy and must be continued. Requirements typically increase in the third trimester and during labour. Hydrocortisone is considered safe during breastfeeding at replacement doses. High-dose anti-inflammatory use should be discussed with your clinician.
Speak to a Clinician About Treatment
Getting advice no longer means sitting in a waiting room. Through The GP Service, you can consult with a licensed clinician in minutes — from home, on your lunch break, or wherever works for you. If treatment is clinically appropriate, your clinician can issue a prescription during the consultation. A consultation does not guarantee a prescription.
The treatment you need, when you need it.
Hydrocortisone FAQs
Both are corticosteroids but differ in potency and mineralocorticoid activity. Hydrocortisone is the closest synthetic equivalent to natural cortisol, with moderate glucocorticoid and significant mineralocorticoid activity — making it ideal for adrenal replacement. Prednisolone is approximately 4 to 5 times more potent as a glucocorticoid with minimal mineralocorticoid activity, making it preferred for anti-inflammatory use. For conditions requiring immunosuppression, prednisolone allows effective dosing with less fluid retention.
Topical hydrocortisone 1% is a mild steroid and is generally safe for short-term use on body skin. Prolonged use — particularly on the face, around the eyes, or in skin folds — can cause local side effects including skin thinning, stretch marks, and increased susceptibility to skin infections. It should not be used continuously for more than 1 to 2 weeks without clinical reassessment.
Sick day rules are guidelines for patients with adrenal insufficiency about when and how to increase their hydrocortisone dose during periods of physiological stress. As a general principle: double the dose for mild illness (e.g. a fever, cold, or minor infection); triple the dose for significant illness (high fever, vomiting, significant pain); administer emergency injectable hydrocortisone (and call 999) if you are unable to keep oral medication down. Your endocrinologist or clinician will provide specific personalised guidance.
Topical hydrocortisone is indeed a corticosteroid (steroid) cream used for eczema and other inflammatory skin conditions. It is the mildest class of topical corticosteroid available (Class 4 — mild potency in the UK classification), suitable for mild eczema or contact dermatitis. Stronger topical steroids (e.g. betamethasone valerate, clobetasol propionate) are used for more resistant or severe conditions and require prescription.