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Recombinant human TSH Pregnancy: UK SPC sections 4.3 and 4.6: CONTRAINDICATED in pregnancy. Animal reproduction studies have not been conducted; it is not known whether Thyrogen can cause foetal harm when administered to a pregnant woman or whether it can affect reproductive capacity. Thyrogen in combination with diagnostic radioiodine whole body scintigraphy is contraindicated in pregnancy because of the consequent exposure of the foetus to a high dose of radioactive material. Breast-feeding: it is unknown whether thyrotropin alfa or its metabolites are excreted in human milk and a risk to the suckling child cannot be excluded — Thyrogen should not be used during breast-feeding. Fertility: it is not known whether Thyrogen can affect fertility in humans.

Thyrotropin alfa

Brand names: Thyrogen

Thyrotropin alfa is a recombinant human thyroid-stimulating hormone (TSH) used as an adjunct in the follow-up of differentiated thyroid carcinoma. It allows stimulated thyroglobulin testing and radioiodine imaging or remnant ablation without the need to withdraw thyroid hormone therapy.

Adult dose

Dose: 0.9 mg thyrotropin alfa per dose — two doses in total
Route: Intramuscular injection only, into the buttock. After reconstitution with water for injections, 1.0 ml of solution contains 0.9 mg thyrotropin alfa. Must NOT be administered intravenously.
Frequency: Two doses administered at a 24-hour interval
SPECIALIST SUPERVISION (section 4.2): "Therapy should be supervised by physicians with expertise in thyroid cancer." VERBATIM section 4.2: "The recommended dose regimen is two doses of 0.9 mg thyrotropin alfa administered at a 24-hour interval by intramuscular injection only." "After reconstitution with water for injection, 1.0 ml solution (0.9 mg thyrotropin alfa) is administered by intramuscular injection to the buttock." TIMING WITH RADIOIODINE AND THYROGLOBULIN TESTING: "For radioiodine imaging or ablation, radioiodine administration should be given 24 hours following the final Thyrogen injection. Diagnostic scintigraphy should be performed 48 to 72 hours following radioiodine administration, whereas post-ablation scintigraphy may be delayed additional days to allow background activity to decline. For diagnostic follow-up serum thyroglobulin (Tg) testing, the serum sample should be obtained 72 hours after the final injection of Thyrogen. Use of Thyrogen with Tg testing in follow up of post-thyroidectomy well differentiated thyroid cancer patients should be in accordance with official guidelines." NO MAXIMUM DOSE IS STATED — section 4.2 gives a fixed two-dose regimen and no higher dose or ceiling, so no maxDose has been entered. ELDERLY: "Results from controlled trials indicate no difference in the safety and efficacy of Thyrogen between adult patients less than 65 years and those greater than 65 years of age, when Thyrogen is used for diagnostic purposes. No dose adjustment is necessary in elderly." RENAL: "elimination of Thyrogen is significantly slower in dialysis-dependent end stage renal disease (ESRD) patients, resulting in prolonged elevation of thyroid stimulating hormone (TSH) levels for several days after treatment. This may lead to increased risk of headache and nausea. There are no studies of alternative dose schedules of Thyrogen in patients with ESRD to guide dose reduction in this population. In patients with significant renal impairment the activity of radioiodine should be carefully selected by the nuclear medicine physician." HEPATIC: "The use of Thyrogen in patients with reduced liver function does not warrant special considerations." Some sections of the product information we used were incomplete — check the full SPC. NOT USED: the bundle's openFDA record is "GUNA-GERIATRICS" (Guna spa, 2018-12-22), an unrelated oral homeopathic drops product containing no thyrotropin alfa; nothing from it was carried into this draft.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to bovine or human thyroid stimulating hormone or to any of the excipients listed in section 6.1
  • Pregnancy (Thyrogen in combination with diagnostic radioiodine whole body scintigraphy is contraindicated in pregnancy because of the consequent exposure of the foetus to a high dose of radioactive material)
  • Section 4.4: Thyrogen should not be administered intravenously
  • Section 4.2: due to a lack of data on the use of Thyrogen in children, it should be given to children only in exceptional circumstances

Side effects

  • Very common: nausea (approximately 11% of patients)
  • Very common: dizziness, headache (headache in approximately 6% of patients)
  • Very common: fatigue, asthenia
  • Common: vomiting
  • Common: neoplasm swelling, metastatic pain
  • Common: urticaria, rash
  • Common: neck pain, back pain
  • Common: influenza-like illness, pyrexia, chills, feeling hot
  • Common: TSH decreased
  • Uncommon: influenza; ageusia, dysgeusia, paraesthesia; palpitations; flushing; dyspnoea; diarrhoea; pruritus, hyperhidrosis; arthralgia, myalgia
  • Uncommon: injection site discomfort, pain, pruritus, rash and urticaria
  • Uncommon: hypersensitivity manifestations — urticaria, rash, pruritus, flushing and respiratory signs and symptoms
  • Not known: stroke, tremor
  • Very rare: hyperthyroidism or atrial fibrillation, observed when Thyrogen 0.9 mg has been administered to patients with a partial or entire thyroid gland present
  • Enlargement of residual thyroid tissue or metastases can occur, leading to acute symptoms depending on anatomical location — hemiplegia, hemiparesis or loss of vision in patients with CNS metastases; laryngeal oedema, respiratory distress requiring tracheotomy, and pain at the site of metastasis have also been reported
  • This side-effect list may be incomplete — check the full SPC.

Monitoring

  • Record the name and batch number of the administered product to improve traceability of this biological medicinal product (section 4.4)
  • Give radioiodine 24 hours after the final Thyrogen injection; perform diagnostic scintigraphy 48 to 72 hours after radioiodine administration (section 4.2)
  • Obtain the serum thyroglobulin (Tg) sample 72 hours after the final Thyrogen injection (section 4.2)
  • Both TgAb and Tg assays are needed — Tg autoantibodies can be expected in 18-40% of patients with differentiated thyroid cancer and may cause false negative serum Tg measurements (section 4.4)
  • It is not recommended to perform TSH assays after Thyrogen administration, as antibodies which could interfere with endogenous TSH assays cannot be excluded (section 4.8)
  • False negative results may occur; if a high index of suspicion for metastatic disease persists, consider a confirmatory withdrawal whole body scintigraphy and Tg testing (section 4.4)
  • Carefully evaluate benefit-risk in high risk elderly patients with heart disease (valvular heart disease, cardiomyopathy, coronary artery disease, prior or current tachyarrhythmia including atrial fibrillation) who have not undergone thyroidectomy, and in patients with significant residual thyroid tissue — Thyrogen causes a transient but significant rise in serum thyroid hormone concentration in these patients (section 4.4)
  • Consider pre-treatment with corticosteroids in patients in whom local tumour expansion may compromise vital anatomic structures — patients with metastases in confined spaces such as the brain, spinal cord and orbit, or disease infiltrating the neck, may experience local oedema or focal haemorrhage (section 4.4)

Clinical monograph

How it works

It is recombinant human TSH that binds TSH receptors on thyroid follicular (and thyroid cancer) cells, stimulating iodine uptake and thyroglobulin production, thereby enhancing the sensitivity of thyroglobulin measurement and radioiodine studies.

Prescribing in practice

  • In patients with residual thyroid tissue or metastases, TSH stimulation can cause local tumour swelling, which may be hazardous where expansion could compress nearby structures, so this risk should be considered and pretreatment with corticosteroids contemplated.
  • It is used together with thyroglobulin measurement and, where indicated, radioiodine, and results should be interpreted by clinicians experienced in thyroid cancer follow-up.
  • It is given by intramuscular injection and is not a substitute for thyroid hormone replacement therapy.

Monitoring

Monitor stimulated serum thyroglobulin (with antibody status), together with any imaging results, and observe for symptoms of tumour swelling after administration.

Counselling the patient

  • This medicine is given as injections, usually as part of scheduled thyroid cancer follow-up.
  • It means you can usually stay on your thyroid hormone tablets rather than stopping them.
  • Report any neck swelling, pain, or breathing difficulty after the injections.

Evidence & guidelines

Its use in thyroglobulin-stimulated testing and radioiodine remnant ablation is supported by clinical trials in differentiated thyroid cancer follow-up.

Reference: SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways