TRH (Thyrotropin-Releasing Hormone) Dosing & Reconstitution Guide

TRH (protirelin) is a hypothalamic tripeptide that stimulates TSH and prolactin release from the anterior pituitary. It is approved as a diagnostic agent for thyroid function testing and has been studied for antidepressant and analeptic properties.

Mechanism: TRH binds to TRH receptors (TRHR1/R2) on thyrotroph and lactotroph cells in the anterior pituitary, activating Gq-coupled signaling via phospholipase C to stimulate TSH and prolactin secretion. It also has direct CNS effects including arousal, mood elevation, and respiratory stimulation.

Route: Intravenous (diagnostic)

Frequency: Single dose

Dose Range: 200–500 mcg IV bolus (TRH stimulation test)

Thyroid function testing Well-established diagnostic use worldwide. FDA-approved as Protirelin for TRH stimulation test.

Antidepressant effects Multiple human studies showing transient mood improvement (Prange AJ et al., Lancet, 1972; Gary KA et al., J Affect Disord, 2003). Short duration of action limits clinical utility.

The safety profile of TRH has been characterized by several common adverse effects that warrant consideration in research settings. Notably, nausea, flushing, and an increased urge to urinate have been documented following administration. Additionally, certain contraindications must be acknowledged to mitigate risks associated with TRH use. Individuals with coronary artery disease may be at heightened risk due to potential blood pressure spikes following administration, while those with seizure disorders should be cautious, as TRH may provoke seizures. These safety considerations highlight the importance of thorough participant screening and monitoring during research involving TRH.