Levonorgestrel

證據等級: L5

預測適應症: 6 個

Levonorgestrel: From Contraception to Acne

One-Sentence Summary

Levonorgestrel (LNG) is a synthetic progestin widely used as a hormonal contraceptive, available in combined oral contraceptives (COC), intrauterine devices (IUD), and emergency contraception formulations. The TxGNN model predicts it may be effective for Acne (Disease), with 5 clinical trials and 20 publications currently supporting this direction — though the mechanistic relationship is notably complex and bidirectional, requiring careful interpretation.

Quick Overview

Item	Content
Original Indication	Contraception (no India regulatory records on file)
Predicted New Indication	Acne (Disease)
TxGNN Prediction Score	99.88%
Evidence Level	L3
India Market Status	✗ Not Marketed
Number of Registrations	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Levonorgestrel is a 19-nortestosterone-derived synthetic progestin with well-documented androgenic activity, classifying it among the more androgenic members of the progestin family (PMID 7825629). It functions primarily as a hormonal contraceptive — either as the progestin component of combined oral contraceptives (COC) paired with ethinylestradiol (EE), or as a standalone progestin in intrauterine devices and subdermal implants. Detailed MOA data is currently unavailable from the regulatory database; the mechanistic picture below is derived from the published literature.

The relationship between LNG and acne is mechanistically bidirectional. When used in combination with EE as a COC, the estrogen component raises sex hormone-binding globulin (SHBG), lowers circulating free testosterone, and suppresses sebaceous gland activity — all of which can improve acne. A placebo-controlled RCT (PMID 12196750) demonstrated that a low-dose COC containing 20 µg EE + 100 µg LNG significantly improved biochemical markers of androgenicity and was effective against moderate acne. This is the strongest signal supporting the TxGNN prediction.

However, LNG used alone exhibits partial androgen receptor (AR) agonist activity that can stimulate sebaceous glands and elevate free androgens — potentially worsening rather than treating acne. Comparative studies consistently show LNG-containing pills are less favorable for dermatological outcomes than COCs formulated with anti-androgenic progestins (e.g., drospirenone, chlormadinone acetate). In short, the beneficial acne signal belongs to the LNG+EE combination, not LNG as a standalone agent.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT00480532	N/A	Completed	131	Evaluates doxycycline for reducing breakthrough bleeding during continuous LNG-containing COC use; acne is incidental context, not a primary endpoint
NCT01650168	N/A	Completed	101,498	Large safety cohort comparing nomegestrol acetate/estradiol vs. LNG-containing COC; primary endpoints are cardiovascular and VTE safety, not acne efficacy
NCT00161226	N/A	Terminated	44	LNG intrauterine system for endometrial cancer prevention in obese women; oral progestin-associated acne cited as background rationale, no acne treatment endpoint
NCT05570786	Phase 2	Completed	100	Double-blind RCT of gestrinone subdermal implant for endometriosis-associated pelvic pain; study drug is gestrinone (not LNG), indirect relevance only
NCT05492487	Phase 2	Unknown	60	LNG-IUS (Mirena) vs. megestrol for atypical endometrial hyperplasia; no acne-related endpoints

⚠️ Important: No registered trial directly evaluates LNG monotherapy for acne treatment. All acne-relevant signals derive from LNG+EE combination oral contraceptive studies.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
12196750	2002	RCT	J Am Acad Dermatol	Placebo-controlled trial: low-dose COC (20 µg EE + 100 µg LNG) significantly improved moderate acne; effect attributed to EE-driven SHBG elevation and androgen suppression
6084924	1984	Clinical Study	Acta Derm Venereol	LNG+EE OC raised SHBG and reduced free testosterone in female acne patients; pre-treatment androgen abnormalities found in 57% of subjects
7825629	1995	Review	Am J Medicine	LNG classified as a highly androgenic progestin (19-nortestosterone derivative); its androgenic activity is identified as an unfavorable property in acne management
21895044	2011	Comparative Review	Am J Clin Dermatol	EE/chlormadinone acetate superior to EE/LNG for acne, hirsutism, and seborrhea; anti-androgenic progestins preferred for pilosebaceous unit disorders
15025547	2004	Review	Drugs	EE/CMA significantly more effective than EE/LNG 0.03/0.15 mg for mild-to-moderate papulopustular facial acne in a controlled comparison
16796485	2006	Review	J Womens Health	Drospirenone-containing COC outperforms LNG-containing COC in reducing acne vulgaris and hirsutism due to antimineralocorticoid and antiandrogenic properties
11727177	2001	Review	Semin Reprod Med	LNG-IUS produces strong antiproliferative effect on endometrium; systemic LNG exposure via IUD is low — limited relevance to systemic acne treatment
14688179	2004	Cohort	Hum Reprod	LNG-IUS improved symptoms of endometriosis; primarily a local progestogenic effect with low systemic androgenic exposure
32909630	2020	Cochrane Review	Cochrane Database Syst Rev	LNG-IUS effective for endometrial hyperplasia treatment; no acne efficacy endpoints reported
11091988	2000	Review	Obstet Gynecol Clin NA	LNG implants prevent pregnancy via ovulation inhibition, cervical mucus changes, and endometrial alteration; androgenic activity of LNG noted as a pharmacological property

India Market Information

Levonorgestrel currently has no registered products in India’s drug regulatory database, with zero active licenses on record.

Note: This does not reflect global availability. LNG is widely marketed internationally under brand names including Mirena and Kyleena (hormonal IUDs), Plan B / Postinor (emergency contraception), and as the progestin component of numerous combined oral contraceptive formulations.

Safety Considerations

Drug Interactions (162 interactions identified; representative moderate-level interactions shown):

Interacting Drug	Level	Clinical Note
Insulin aspart, lispro, degludec, isophane, zinc (multiple formulations)	Moderate	LNG may impair insulin sensitivity and compromise glycemic control
Canagliflozin, Dapagliflozin, Ertugliflozin (SGLT2 inhibitors)	Moderate	LNG may counteract glucose-lowering effects of SGLT2 inhibitors
Exenatide, Liraglutide (GLP-1 agonists)	Moderate	Risk of reduced antidiabetic efficacy
Linagliptin, Nateglinide	Moderate	Potential for compromised glycemic management
Aprepitant	Moderate	CYP3A4 induction may reduce LNG plasma concentrations
Clotrimazole	Moderate	CYP enzyme interaction; potential for altered LNG systemic exposure
Acarbose, Glycerol phenylbutyrate	Moderate	LNG’s glucocorticoid-like metabolic effects may antagonize antidiabetic agents

⚠️ The high concentration of interactions with antidiabetic drug classes reflects LNG’s known effect on glucose metabolism and insulin resistance — a clinically important consideration in patients with diabetes or metabolic syndrome.

Please refer to the package insert for full warnings and contraindications (currently unavailable for India; data gap DG001 pending resolution).

Conclusion and Next Steps

Decision: Hold

Rationale: The clinical evidence for LNG in acne derives entirely from LNG+EE combination oral contraceptives, not from LNG monotherapy. LNG’s intrinsic androgenic (AR partial agonist) activity means that, without an estrogenic counterpart to raise SHBG, LNG may actively worsen acne — making it fundamentally unsuitable as a standalone acne therapy. Comparative head-to-head data consistently rank LNG-containing regimens below anti-androgenic progestins for dermatological indications.

To proceed, the following is needed:

Formulation strategy clarification: Determine whether the intended target is the LNG+EE combination (not LNG monotherapy); this changes the regulatory and clinical development pathway entirely
MOA data retrieval: Complete DrugBank API query to formally document mechanism of action (Data Gap DG002)
Safety package completion: Retrieve full TFDA/CDSCO package insert for warnings and contraindications (Data Gap DG001, Blocking severity)
Preclinical clarification: Obtain data on LNG’s net effect on sebaceous gland activity in the absence of exogenous estrogen, to resolve the bidirectionality concern
Comparative efficacy design: If the combination indication is pursued, plan head-to-head trials against anti-androgenic COCs (drospirenone-EE, CMA-EE) to demonstrate non-inferiority or superiority
India regulatory pathway: With zero existing registrations, any new indication would require a full new drug application to CDSCO
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.