Triregol Tablets

When both hormones in a combined pill change dose across the cycle rather than just one, the pharmacological design becomes significantly more complex. Most combined pills fix one hormone and vary the other, or fix both. Triregol varies both levonorgestrel and ethinylestradiol simultaneously across three phases — a dual-stepped architecture that distinguishes it from every monophasic pill and from the norethisterone-based Synphase, where only the progestogen changes.

Triregol is a triphasic combined oral contraceptive tablet licensed in the United Kingdom for the prevention of pregnancy. It contains levonorgestrel and ethinylestradiol across three distinct dose phases within a single 21-tablet pack. It is manufactured by Gedeon Richter UK Ltd and is the generic equivalent of Logynon. This page explains what the triphasic levonorgestrel structure means clinically, how the dual-phase variation works, and what you need to consider before starting a consultation.

Triregol is the generic version of Logynon, one of the original triphasic combined pills in UK prescribing. Both Triregol (Gedeon Richter) and Logynon (Bayer) contain identical active ingredients at identical doses across all three phases. NHS and FSRH guidance treat them as clinically interchangeable. If your pharmacy supplies Triregol when you expect Logynon, the contraceptive content is unchanged.

What makes Triregol pharmacologically distinct from every other combined pill in this series is that both hormones change dose across the cycle. Levonorgestrel steps up from 50 to 75 to 125 micrograms. Ethinylestradiol changes from 30 to 40 and back to 30 micrograms. This dual variation is the defining structural feature of this preparation and the reason the pack must be taken in strict phase sequence.

Levonorgestrel is a second-generation synthetic progestogen. MHRA guidance places levonorgestrel-containing combined pills in the lowest VTE risk category among combined oral contraceptives, lower than third-generation progestogen pills such as those containing desogestrel, gestodene, or norgestimate. This risk classification applies to Triregol as it does to monophasic levonorgestrel preparations such as Rigevidon and Microgynon 30.

The 21-tablet pack contains three tablet types, colour-coded to distinguish each phase. All 21 tablets must be taken in the sequence shown on the blister strip. After day 21, a seven-day break follows before the next pack begins.

Triregol delivers contraceptive protection through ovulation suppression, cervical mucus thickening, and endometrial change – the standard combined pill triad. What is specific to Triregol is the pharmacological reasoning behind varying both hormones simultaneously rather than fixing one and stepping the other.

Why Both Hormones Change

In a monophasic combined pill, the progestogen and oestrogen doses remain constant throughout the active phase. A triphasic approach attempts to approximate the hormone profile of a natural cycle more closely by stepping doses rather than delivering a constant level. In Triregol, the levonorgestrel rises across all three phases: 50 mcg, then 75 mcg, then 125 mcg. The ethinylestradiol rises slightly in phase 2 (40 mcg) before returning to 30 mcg in phase 3. This dual stepping is designed to use the lowest effective dose of each hormone at each stage of the cycle while maintaining consistent contraceptive protection throughout.

Ovulation Suppression

Levonorgestrel and ethinylestradiol act together to suppress follicle-stimulating hormone and luteinising hormone from the pituitary gland. The luteinising hormone surge that triggers ovulation is inhibited. Even during phase 1, where the levonorgestrel dose is at its lowest (50 mcg), the combined hormonal suppression is sufficient to prevent follicle maturation when tablets are taken correctly.

Cervical Mucus Thickening

Levonorgestrel thickens cervical mucus throughout all three active phases. The degree of thickening is proportional to levonorgestrel levels, meaning the cervical mucus effect is maintained at a lower baseline in phase 1 and strengthens progressively across phases 2 and 3 as the levonorgestrel dose rises. This graduated mucus effect complements the primary ovulation suppression mechanism.

The Withdrawal Bleed

After the 21st tablet, both levonorgestrel and ethinylestradiol levels fall as the hormones clear from circulation. The endometrium, which has been maintained in a suppressed state, responds by shedding during the seven-day break. Because Triregol ends with the highest levonorgestrel phase (125 mcg in phase 3), the hormonal drop into the break is more pronounced than in preparations that end at a lower dose. The withdrawal bleed typically begins two to three days after the last active tablet.

Taking Triregol in the correct sequence is not a suggestion. Both hormones change across all three phases, which means taking a phase 3 ochre tablet on day 2 is not simply taking a higher progestogen dose early – it also delivers a different oestrogen exposure. The blister strip provides the correct day-by-day sequence. Follow it without deviation.

When to Start

Starting on day 1 of your period provides immediate protection from the first tablet. Beginning between days 2 and 5 requires barrier contraception for the first seven days.

Switching from a monophasic combined pill: take the first Triregol tablet the day after the last active tablet of your previous pack, or after the last inactive tablet if your previous pill had placebo days. Protection continues without interruption.

Switching from Logynon: no change to the schedule is needed. Triregol and Logynon are clinically equivalent and interchangeable. Start the new pack as you would have started the next Logynon pack.

Switching from a progestogen-only pill: start Triregol on any day and use barrier contraception for the first seven days.

The 21-Day Course and Seven-Day Break

One tablet daily in sequence for 21 consecutive days. Seven days off. New pack on day 29 whether or not the withdrawal bleed has finished. The break must not exceed seven days. A longer gap allows ovarian follicle activity to resume before the new pack re-establishes suppression. The first phase 1 light brown tablet of the new pack is always the correct tablet on day 29.

Missed Tablets

Under 24 hours late: take it immediately, continue in sequence, protection is maintained.

More than 24 hours late: take the missed tablet immediately, take the next one at the usual time even if two fall on the same day, and use barrier contraception for seven days. Because both hormones vary across phases, take particular care to continue from the correct position in the sequence after a missed tablet.

Two or more consecutive tablets missed: take only the most recently missed tablet, discard the rest, continue from the correct sequence position, and use condoms for seven days. If missed tablets fell in week one of the pack and unprotected sex occurred in the preceding seven days, seek advice about emergency contraception without delay.

Important Note: Triregol tablets are not interchangeable between phases. Phase 1, phase 2, and phase 3 tablets each contain different doses of both hormones. If you are unsure which tablet to take after a missed dose, check the blister strip and contact your pharmacist before continuing.

Triregol is a triphasic preparation. The dose of both active hormones changes at each phase. The full composition of the 21-tablet pack is shown below:

Total levonorgestrel across the 21-day course: (6 x 50 mcg) + (5 x 75 mcg) + (10 x 125 mcg) = 300 + 375 + 1,250 = 1,925 micrograms.

Total ethinylestradiol across the 21-day course: (6 x 30 mcg) + (5 x 40 mcg) + (10 x 30 mcg) = 180 + 200 + 300 = 680 micrograms.

How Triregol Compares to Synphase

Both Triregol and Synphase are triphasic combined pills. The structural difference is significant:

1. Triregol: levonorgestrel plus ethinylestradiol, both hormones change across three phases, three different tablet types
2. Synphase: norethisterone plus ethinylestradiol 35 mcg, only the norethisterone changes, ethinylestradiol is fixed throughout

In Triregol, the oestrogen rises in phase 2 and returns to the lower level in phases 1 and 3. In Synphase, the oestrogen never changes. This means that Triregol's phase 2 tablets deliver a higher combined oestrogen and progestogen exposure than any single tablet in the Synphase pack. These are not interchangeable preparations and should not be treated as equivalent triphasic options without prescriber guidance.

Triregol and Logynon: Confirmed Equivalence

Triregol is the generic version of Logynon. All phase compositions are identical. Pharmacies may dispense either preparation. No prescriber review is required when switching between Triregol and Logynon, as the active content is the same. This is the only preparation pair in this catalogue where a brand-to-generic switch requires no clinical input.

Triregol's side effect profile shares the characteristics of levonorgestrel-based combined pills, with one additional consideration: because both hormones vary across phases, some women notice that their experience of the pill changes at phase transition points within the same pack.

Phase-Related Effects

The rise in ethinylestradiol during phase 2, from 30 to 40 micrograms, may produce a temporary increase in oestrogen-related effects such as breast tenderness or nausea during the five-day phase 2 window. These typically settle as phase 3 returns the ethinylestradiol dose to 30 mcg. If oestrogen-related side effects are noticeably worse during the middle five tablets of each pack and persist beyond three cycles, discuss this with your prescriber.

Bleeding Pattern

Breakthrough spotting is more commonly reported in triphasic pills than in monophasic preparations, particularly in the first two cycles. This is related to the dose transitions at phase change points causing brief periods of endometrial instability. Spotting that settles by cycle three is considered an expected adjustment response. Persistent or heavy bleeding beyond three cycles warrants a prescriber review.

Common Side Effects

1. Headache
2. Nausea, particularly during phase 2 when the oestrogen dose is slightly higher
3. Breast tenderness
4. Mood changes, including low mood
5. Changes in libido
6. Changes in vaginal discharge

Less Common Effects

1. Weight changes
2. Contact lens intolerance
3. Chloasma: skin darkening on the face, worsened by sun exposure

Serious Signs Requiring Urgent Action

Stop Triregol immediately and seek emergency help if you experience:

1. Sudden chest pain, difficulty breathing, or coughing up blood
2. Swelling, warmth, redness, or pain in one leg
3. Sudden severe headache, visual disturbance, slurred speech, or one-sided weakness
4. Severe acute abdominal pain
5. Yellowing of the skin or whites of your eyes

Blood Clot Risk

Levonorgestrel-containing combined pills including Triregol sit in the lowest VTE risk category among combined oral contraceptives, as confirmed by MHRA guidance. This is lower than the risk associated with third-generation progestogen pills. The triphasic dose format does not change this classification; the progestogen type and generation drive the risk category, not the dose architecture. Your individual risk factors are assessed by the prescriber before any prescription is issued.

Drug Interactions

Enzyme-inducing medicines reduce circulating levels of levonorgestrel and ethinylestradiol, compromising contraceptive effectiveness. These include rifampicin, antiepileptics such as phenytoin, carbamazepine, phenobarbital, and topiramate, some HIV antiretrovirals, and St John's Wort. Declare every medicine, supplement, and herbal product at every consultation.

Eligibility for Triregol covers standard combined pill criteria, with the additional practical consideration of whether the triphasic dual-variable format is appropriate for your daily routine.

Triregol Is Not Suitable If You:

1. Have ever had a blood clot: DVT, pulmonary embolism, stroke, or heart attack
2. Have migraine with aura: an absolute contraindication to all oestrogen-containing combined pills
3. Have uncontrolled high blood pressure
4. Have active or past liver disease or liver tumours
5. Have or have had breast cancer or another hormone-sensitive malignancy
6. Are pregnant
7. Are breastfeeding a baby under six weeks old
8. Smoke and are aged 35 or older
9. Have diabetes with established vascular complications

Triregol May Be Appropriate If You:

1. Are a healthy adult woman with no contraindications to oestrogen-containing contraception and levonorgestrel specifically
2. Have previously taken Logynon and are being dispensed Triregol as the generic equivalent
3. Are already established on Triregol and are seeking a continuation prescription
4. Can reliably follow a three-phase colour-coded sequence every day and understand that tablets from different phases contain different doses of both hormones
5. Have no personal or family history suggesting elevated VTE risk

Discuss With Your Prescriber First If You:

1. Are starting a triphasic pill for the first time without previous combined pill experience, as a monophasic preparation may be a more straightforward starting point
2. Have experienced phase-related side effects on Logynon and want to discuss whether switching to a monophasic levonorgestrel pill such as Rigevidon or Microgynon 30 would improve tolerability
3. Smoke and are under 35
4. Have a BMI above 30
5. Have a first-degree family member who developed a blood clot before the age of 50
6. Have migraines of any type

A prescription for Triregol at Pharmacy Planet begins with a clinical consultation reviewed by a registered prescriber. For Triregol, the prescribing assessment covers three areas that do not all apply to a monophasic levonorgestrel consultation.

First, the prescriber confirms standard combined pill eligibility: VTE risk, migraine history, blood pressure, smoking status, and any current medicines that interact with levonorgestrel or ethinylestradiol.

Second, the prescriber considers whether the triphasic format with both hormones varying is clinically appropriate for you, or whether a monophasic levonorgestrel preparation such as Rigevidon or Microgynon 30 would achieve the same contraceptive outcome with simpler dosing. Triregol is often prescribed for women already established on Logynon. For new combined pill users with no specific reason to use a triphasic format, a prescriber may recommend starting with a monophasic preparation.

Third, if you are switching from Logynon, the prescriber simply confirms the switch is appropriate and that your health profile has not changed since your last review. This is the straightforward case.

The consultation outcome may be a prescription for Triregol, a recommendation for a monophasic levonorgestrel alternative, a suggestion to consider a different combined pill class, a request for further information, or a referral for a face-to-face review. Completing the questionnaire opens the clinical process. Repeat prescriptions are individually reviewed with no automatic renewal.

Store Triregol below 25°C in a cool, dry location away from direct sunlight. The blister strip is clinically essential for this preparation: it shows the three-phase sequence with colour coding that distinguishes phase 1 light brown tablets, phase 2 white tablets, and phase 3 ochre tablets. Removing tablets from the strip in bulk removes the visual cues that guide correct sequence use. Keep all tablets in the original blister strip until the moment of use.

Check the expiry date on the outer carton before each new pack. Store all medicines out of sight and reach of children. Return unused or expired tablets to a UK pharmacy for safe disposal under Duty of Care regulations, free of charge. Do not flush tablets or place them in household waste.

This reference guide compares the contraceptive preparations available at Pharmacy Planet, grouped by delivery method and formulation type. Every preparation is a Prescription Only Medicine. A registered prescriber will review your individual health profile, contraceptive history, and risk factors before recommending any preparation. This table is a clinical reference, not a recommendation.

Multiphasic combined pills change hormone doses at defined points across the active tablet course. The table below compares the triphasic and quadriphasic preparations available at Pharmacy Planet by progestogen stepping, oestrogen stepping, VTE risk, and key distinguishing features.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.

Triregol is the generic equivalent of Logynon, and for most women already established on that preparation, the transition to Triregol is straightforward. But straightforward does not mean unchecked. A levonorgestrel triphasic still requires a prescriber to review your VTE risk, migraine history, smoking status, and current medicines before issuing a prescription. And for anyone considering a triphasic format for the first time, the prescriber needs to make an active decision that this dual-variable design is appropriate rather than defaulting to something more complex than necessary.

At Pharmacy Planet, every Triregol consultation is reviewed by a registered prescriber who makes that judgement individually. If a monophasic levonorgestrel preparation would serve you just as well with less complexity, the prescriber will say so.

• Gedeon Richter UK Ltd. Triregol film-coated tablets – Summary of Product Characteristics. Available at: www.medicines.org.uk/emc. Accessed May 2026.
• Faculty of Sexual and Reproductive Healthcare (FSRH). Combined Hormonal Contraception – Clinical Guidance. Available at: www.fsrh.org. Accessed May 2026.
• NHS. Combined pill – your contraception guide. Available at: www.nhs.uk/conditions/contraception/combined-contraceptive-pill. Accessed May 2026.
• British National Formulary (BNF). Ethinylestradiol with levonorgestrel. Available at: bnf.nice.org.uk. Accessed May 2026.
• MHRA. Combined hormonal contraceptives and venous thromboembolism. Available at: www.gov.uk. Accessed May 2026.