Overview
Cabergoline is classified as a PCT (post-cycle therapy) and ancillary compound. Ergot-derived dopamine D2 receptor agonist.
With a half-life of ~2.6 days (63 hours), Cabergoline supports less frequent dosing schedules. Taken orally, it has a bioavailability of approximately 95% via its primary route.
Half-life approximately 63 hours. Long duration of action supports twice-weekly dosing intervals. One-compartment model.
Mechanism of Action
Cabergoline's pharmacological activity involves the following key pathways:
Dopamine Receptor Agonism
Cabergoline activates dopamine D2 receptors in the pituitary, which inhibits prolactin secretion from lactotroph cells.
Prolactin Suppression
By stimulating dopamine receptors, Cabergoline reduces circulating prolactin levels in a dose-dependent manner.
Dosing Protocols
The following protocols represent commonly observed dosing patterns. These are observational summaries, not recommendations.
Dose
0.25 mg/day
Route
Oral
Frequency
Every other day
Duration
4-8 weeks
Dose
0.5 mg/day
Route
Oral
Frequency
Every other day
Duration
4-8 weeks
Frequently Asked Questions
What is cabergoline and how does it work?
Cabergoline is a potent, long-acting dopamine D2 receptor agonist derived from the ergot alkaloid family. It mimics the action of dopamine by binding to D2 receptors on lactotroph cells in the anterior pituitary gland, directly inhibiting prolactin secretion. It also has affinity for D3, D4, and several serotonin receptor subtypes. Its primary use is the management of elevated prolactin levels (hyperprolactinemia).
What is the half-life of cabergoline and how often is it dosed?
Cabergoline has an elimination half-life of approximately 63–69 hours, making it one of the longest-acting dopamine agonists available. This extended half-life allows for twice-weekly dosing rather than daily administration. A single dose has been observed to produce prolactin-lowering effects lasting up to 14 days, with peak suppression occurring around 48 hours after administration.
Why is cabergoline used alongside 19-nor compounds?
19-nortestosterone derivatives such as nandrolone and trenbolone are commonly associated with elevated prolactin levels through their progestogenic activity. Elevated prolactin can manifest as reduced libido, mood changes, and other effects. Cabergoline is used alongside these compounds to maintain prolactin within a normal range. Bloodwork confirmation of elevated prolactin is generally recommended before initiating use.
What are the common side effects of cabergoline?
The most commonly reported side effects include nausea (particularly at higher doses or during initial titration), dizziness, headache, and orthostatic hypotension (lightheadedness when standing). At prolonged high doses, cardiac valvulopathy has been observed due to 5-HT2B serotonin receptor activation – though this is typically associated with the higher doses used in Parkinson’s disease treatment rather than the lower doses used for prolactin management.
How does cabergoline affect libido and dopamine?
As a dopamine agonist, cabergoline increases dopaminergic activity in the brain beyond just prolactin suppression. This is commonly associated with increased libido, reduced refractory period, and improved mood – effects attributed to enhanced dopamine signaling in the mesolimbic reward pathway. These effects are dose-dependent and are among the reasons cabergoline is preferred over older dopamine agonists like bromocriptine.
How does cabergoline compare to pramipexole for prolactin management?
Both compounds effectively lower prolactin, but they differ in key ways. Cabergoline has a much longer half-life (63–69 hours vs 8 hours), allowing twice-weekly dosing compared to pramipexole’s daily requirement. Cabergoline is generally considered the first-line choice due to its convenience, potency, and well-established efficacy. Pramipexole is sometimes preferred for its D3 receptor selectivity and lower cost, but it carries more pronounced sedation and requires careful dose titration.