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PCT & hormone control

Cabergoline

The long-acting dopamine D2 agonist - lowers prolactin and protects the hormone axis.

2 min read 5 sources

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White tablet bottle with the black TPD label for cabergoline on a white podium, next to a large molecule model of blue and white spheres in a bright lab
Compound approved · since 1996

Summary

At a glance

Sources checked on 26 Oct 2026

Prolactin stably normal
83 %

223 women with raised prolactin, 59 percent on bromocriptine1

Normal after 4 weeks
95 %

highest study dose in the placebo-controlled trial, 0 percent on placebo3

Half-life
63 to 69 h

estimated from urine data of 12 healthy people3

Stopped due to intolerance
3 %

12 percent on bromocriptine1

  • Cabergoline is a long-acting dopamine agonist at the D2 receptor. In the pituitary it slows the release of prolactin at the source.53
  • The half-life is 63 to 69 hours, which is why doses twice a week were enough in the trials.31
  • Compared with bromocriptine prolactin was stably normal in 83 instead of 59 percent of women, stopping due to intolerance occurred in 3 instead of 12 percent.1
  • Nausea, headache and dizziness are common. The label warns of heart valve changes, fibrosis, a drop in blood pressure on standing and impulse control disorders.3
  • According to ChEMBL cabergoline has been approved since 1996. Everything here is the state of research, not a recommendation.5
Profile

Updated June 2026

How long does it stay in the body?

Share left after one dose, calculated with a half-life of ~2.9 days

Half-life ~2.9 days
After 5.8 days: 25 %
Day 2.9 · 50 %Day 5.8 · 25 %Day 8.8 · 12.4 %Day 14.6 · 3.1 %

Simplified model without an absorption phase, half-life from the TPD lexicon.

Class
Dopamine D2 receptor agonist
Use
Oral

1-2x per week

Half-life
about 70 hours
Status
Clinically approved for hyperprolactinemia
Sizes
0.5 to 1 mg

2 sizes in the shop

Contents 14 sections
  1. At a glance
  2. What is cabergoline?
  3. How it works
  4. How to take it
  5. Dosing
  6. When you need it
  7. What the research shows
  8. Research status
  9. Side effects
  10. Storage
  11. Related compounds
  12. FAQ
  13. Glossary
  14. Sources

What is cabergoline?

Cabergoline (also called Caber, brand name Dostinex) is a long-acting dopamine D2 receptor agonist. It lowers blood prolactin very effectively with significantly fewer side effects than older dopamine agonists like bromocriptine.

Clinically approved for hyperprolactinemia and prolactinomas. In the performance world used to counter prolactin elevations from nandrolone, trenbolone or specific 19-nor steroids.

How it works

Cabergoline activates dopamine D2 receptors in the pituitary. That inhibits prolactin release at the source. Effect starts within hours and lasts days due to the long half-life (~70 hours) - so 1-2 doses per week are enough.

High prolactin is problematic: it suppresses testosterone, causes erectile dysfunction, gynecomastia and libido loss. Cabergoline solves the problem at the root.

Where it acts

Where cabergoline acted in studies

Tap a point or a card. Colour = D2 receptor, grey = observed according to the label.

  1. Pituitary

    Activates D2 receptors, prolactin release falls5

    D2
  2. Heart valves

    Cases of valve changes, mostly at high doses in Parkinson's treatment3

    Observed in trials
  3. Lung and pleura

    Fibrosis described, the label advises monitoring3

    Observed in trials
  4. Blood pressure

    Drop in blood pressure on standing in 4 percent, dizziness in 15 percent3

    Observed in trials
  5. Stomach

    Nausea less common than on bromocriptine1

    Observed in trials

Targets in the ChEMBL database5

Compound CHEMBL1201087: one recorded mechanism, agonist with direct binding to the human receptor.

Dopamine D2 receptor
Gene
DRD2
UniProt
P14416
ChEMBL
CHEMBL217
Action
Agonist, direct binding
Glass gland cell with blue molecules in hollows on its surface, only a few pale bubbles still stream out of an opening
Cabergoline slows prolactin release in the pituitary. Symbolic image.

How to take it

Oral tablet, with some food to minimize nausea.

  • 1 tablet = typically 0.25mg or 0.5mg.
  • With food significantly reduces nausea.
  • Ideally in the evening before bed because the first hours can bring dizziness or mild fatigue.

Splitting into 2 doses per week (e.g. Wednesdays and Sundays) keeps levels more stable.

White tablet bottle with the black TPD label for cabergoline, three small white tablets in front, next to it a plate of blueberries, cheese cubes and almonds and a glass of water
With some food, as described in the entry. Symbolic image.

Dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts

When you need it

Cabergoline is not for routine PCT but for targeted use with prolactin-relevant compounds:

  • Nandrolone cycles (Deca, NPP): nandrolone is 19-nor and progestin-active - classic prolactin driver.
  • Trenbolone cycles: tren has a progestin profile similar to nandrolone.
  • Long MK-677 use: can moderately raise prolactin.
  • By symptoms: dropping libido, erectile issues, gyno hint on nandrolone/tren.

For pure testosterone cycles without 19-nor compounds cabergoline is usually not needed.

Comparison

When cabergoline comes up in the lexicon

The entry names compounds that can raise prolactin according to the TPD lexicon. Tap a card to open its entry.

Lowers prolactin Cabergoline D2
19-nor anabolic Deca (Nandrolone Decanoate) AR 19-nor anabolic Trenbolone Enanthate AR Ghrelin receptor agonist MK-677 (Ibutamoren) Ghrelin

Simplified: how much these compounds raise prolactin is not measured in the sources checked here. Only the prolactin lowering by cabergoline is documented. 51

What the research shows

Cabergoline is clinically well validated:

  • Webster et al. 1994: clear superiority over bromocriptine in hyperprolactinemia, plus better tolerability.
  • Pascal-Vigneron et al. 1995: high success rate normalizing prolactin over months.

Study results

What the trials measured

Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.

Results in women with raised prolactin1

459 women without periods due to excess prolactin, 8 weeks blinded, then 16 weeks open

Prolactin stably normal1
Bromocriptine (comparator) 59%
Cabergoline 83%
Ovulation or pregnancy1
Bromocriptine (comparator) 52%
Cabergoline 72%
Still without periods1
Bromocriptine (comparator) 16%
Cabergoline 7%

Values from the abstract. Stomach and gut complaints were less frequent, milder and shorter on cabergoline.

Prolactin normal after 4 weeks3

188 women with raised prolactin, given twice a week

Placebo-controlled trial3
Placebo 0%
Lower study dose 76%
Middle study dose 74%
Highest study dose 95%

Values from the US label (study 1). An even lower group was not effective and is not shown there.

French comparison trial2

120 women from 21 centres, same design as the large trial

Prolactin normal2 56 of 60 versus 27 of 58
Bromocriptine (comparator) 46.6%
Cabergoline 93.3%
Ovulation or pregnancy2
Bromocriptine (comparator) 48.2%
Cabergoline 71.6%

Bromocriptine value for prolactin calculated from 27 of 58, the abstract gives 48.2 percent there.

Glass model of the pituitary gland on a stand in a bright lab, test tube racks and a microscope next to it
The large trials measured prolactin and cycles in women. Symbolic image.

Research status

Where the research stands

Cabergoline has been approved since 1996. On ClinicalTrials.gov 83 trials list cabergoline, the large comparison trials from 1994 and 1995 are not listed there. Shown is a selection of trials testing cabergoline itself. As of 26 Oct 2026. 4

  1. Preclinical Inhibits prolactin release from the pituitary in cell studies
  2. Phase 1 no registered trial
  3. Phase 2 no registered trial
  4. Phase 3 5 trials, 3 completed
  5. Approval since 1996
1,183 participants in phase 3 Planned figures for running trials Approved: ChEMBL lists cabergoline with phase 4 as the highest phase and first approval in 1996.5
Show all 6 phase 3 and 4 trials on a timelineHide timeline 3 completed 3 running 0 with results
Phase 3
Phase 4

Bar: start to primary endpoint (planned for running trials). Green = completed, blue = progress until 26 Oct 2026.

Side effects

  • Nausea: common in the first weeks, minimizable with food and slow titration.
  • Dizziness: can occur on quick standing (orthostatic hypotension).
  • Heart valves: according to the prescribing information valve changes occurred mostly at high doses (above 2mg per day) in Parkinson's treatment. There are also cases at lower doses for raised prolactin, though. The prescribing information therefore requires a heart ultrasound before starting and checks every 6 to 12 months, with existing valve disease cabergoline is ruled out there.
  • Vivid dreams: some report intense dreams.

Tolerability

Side effects compared with placebo

Out of 100 participants per group, how many had the event over 4 weeks.

20 of 100 Placebo
27 of 100 Cabergoline
Event PlaceboCabergoline
Nausea3 20%27%
Headache3 25%26%
Dizziness3 5%15%
Constipation3 0%10%
Drop in blood pressure on standing3 0%4%

The placebo group was small with 20 women. Compared with bromocriptine nausea was less common (29 versus 43 percent), in the French trial stomach and gut complaints overall (36.6 versus 84.5 percent).32

Storage

Store dry and protected from light, out of reach of children. Keep original container closed.

Three white tablet bottles on a bright shelf next to a folded light blue towel
Dry and away from light, bottle closed. Symbolic image.

Related

Related compounds

A different path: all in the TPD lexicon.

Cabergoline
Deca (Nandrolone Decanoate) A typical prolactin driver according to the lexicon NPP (Nandrolone Phenylpropionate) Short nandrolone ester, same question Trenbolone Enanthate Similar profile to nandrolone according to the lexicon MK-677 (Ibutamoren) Can raise prolactin moderately according to the lexicon Arimidex (Anastrozole) Different path: oestrogen instead of prolactin

FAQ

Common questions about Cabergoline

Short answers, each backed by the sources below.

How does cabergoline lower prolactin?

Cabergoline binds as an agonist to the dopamine D2 receptor. Dopamine is the natural brake on the prolactin cells in the pituitary. According to the label it has only low affinity for other receptors such as D1, alpha adrenoceptors and serotonin receptors.53

Is cabergoline approved?

Yes. ChEMBL lists cabergoline as an approved compound with first approval in 1996. On ClinicalTrials.gov 83 trials list cabergoline (as of 26 October 2026). Everything here is the state of research, not a recommendation.54

Is it better than bromocriptine?

In the large comparison trial with 459 women yes: prolactin was stably normal in 83 instead of 59 percent, 72 instead of 52 percent ovulated or became pregnant. Side effects occurred in 68 instead of 78 percent, 3 instead of 12 percent stopped. A French trial with 120 women came to the same result.12

What about the heart valves?

The label requires a heart ultrasound before starting and checks every 6 to 12 months. Valve changes occurred mostly at high doses in Parkinson's treatment, but there are also cases at lower doses. In a cohort study in Parkinson's the rate was 68 per 10,000 person-years, with other drugs 10 to 11.3

Why dizziness on standing?

Cabergoline can lower blood pressure, especially when standing up quickly. In the placebo-controlled trial 15 percent had dizziness and 4 percent a drop in blood pressure on standing, 5 and 0 percent on placebo. The label advises checking blood pressure at the start and during use.3

Can cabergoline affect behaviour?

Yes, the label lists impulse control disorders: new or stronger urges to gamble, increased sexual urges, uncontrolled spending and binge eating. Anyone noticing this should raise it with a doctor.3

Which trials are running right now?

As of 26 October 2026 recruiting trials include a phase 3 trial with 382 planned participants against bromocriptine, a phase 3 trial on the safety of a higher dose in microprolactinomas and a phase 4 trial on metabolism in prolactinomas.4

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

19-nor
A group of anabolics lacking carbon at position 19, such as nandrolone and trenbolone.
Bromocriptine
Older dopamine agonist, shorter-acting and with more stomach and gut complaints.
D2 agonist
A compound that activates the dopamine D2 receptor like dopamine itself.
Gynaecomastia
Enlargement of the breast gland in men.
Half-life
The time until the amount in the blood has fallen by half.
Heart valve fibrosis
Thickening and stiffening of the heart valves by connective tissue. A known warning for ergot-derived dopamine agonists.
Hyperprolactinaemia
Too much prolactin in the blood, for example from a benign pituitary tumour or from drugs.
Orthostatic hypotension
A drop in blood pressure on standing up, often with dizziness or blacking out.
PCT
Post cycle therapy: the phase after an anabolic cycle in which the body's own hormone production is meant to restart.
Pituitary
The gland at the base of the brain that controls many hormones, including prolactin.
Prolactin
Hormone from the pituitary that controls milk production. Too much of it damps the sex hormones.
Prolactinoma
Benign tumour of the pituitary that produces prolactin.

Evidence

Sources

Show all 5 sourcesHide sources 1 Studies1 Trial registry3 Database checked 26 Oct 2026

Studies

  1. Cabergoline versus bromocriptine in 459 women

    Webster et al., New England Journal of Medicine, 1994

    DOI 10.1056/NEJM199410063311403 PMID 7915824
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. Trials on cabergoline on ClinicalTrials.gov

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

Database

  1. French trial against bromocriptine with 120 women (PubMed record)

    Pascal-Vigneron et al., La Presse Médicale, 1995 (ohne DOI)

    PMID 7784413
    Checked 26 Oct 2026 via PubMed
  2. US prescribing information for cabergoline

    DailyMed, U.S. National Library of Medicine (Stand 30.06.2026)

    Checked 26 Oct 2026 via DailyMed, openFDA
  3. Mechanism and approval in ChEMBL

    ChEMBL, EMBL-EBI (CHEMBL1201087)

    Checked 26 Oct 2026 via ChEMBL

In the shop

Cabergoline in the catalog

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