Hair-loss treatments and your genetics

Different treatments, different genetic questions

Topical minoxidil needs an activation step. Finasteride and dutasteride reduce production of DHT, a hormone involved in pattern hair loss. A genetic finding about one pathway does not automatically tell us how a medicine acting on another pathway will work.

Rogaine is a brand of topical minoxidil. The Gene2Rx interpretation is specific to topical use; it does not predict response to oral minoxidil. Open a treatment above for its detailed evidence and practical context.

Why Gene2Rx assesses SULT1A1 rs1042028

rs1042028 is an experimentally characterized decreased-function variant. It changes the SULT1A1 protein at position 213 from arginine to histidine, known as p.Arg213His, R213H, or the characteristic change in SULT1A1*2. Older publications commonly call it rs9282861.

Human platelet studies linked this variant to lower enzyme activity and reduced thermostability. Direct experiments comparing the two enzyme forms also found lower activity with the His213 form using the thyroid hormone T3 as a substrate. Reduced thermostability means enzyme activity is less resistant to heat under laboratory conditions.^[1][2]

This functional evidence matters because SULT1A1 helps activate topical minoxidil. Research has linked follicular enzyme activity to topical response, and a retrospective genetic study reported an association between rs1042028 and minoxidil outcomes. Together, these findings provide the rationale for including the variant in Gene2Rx.^[3][6]

The variant reduces function under studied conditions; it does not make the enzyme universally inactive. The laboratory studies and treatment-response studies answer different questions, and a genotype cannot guarantee hair regrowth. The minoxidil article explains the experiments, their limits, and the supporting sources in detail.

Why finasteride and dutasteride are not currently assessed

Both medicines have relevant genetic research, including experimental work on their enzyme target.^[7] The current gap is a sufficiently supported interpretation of a specific result that Gene2Rx can give an individual customer. Their absence from the report does not mean the medicines are ineffective or that genetics is irrelevant.

Finasteride: researchers have studied variation in SRD5A2 and repeat lengths in the androgen receptor gene, AR. Results for particular repeat markers have not been consistent across studies, and the research has not established a generally applicable prediction of benefit or side effects. Explore the finasteride evidence and coverage explanation.^[8]

Dutasteride: studies have examined genetic effects on both hair response and drug exposure. In an exploratory hair-response study of 42 men, no individual variant remained significant after correction for multiple testing. That makes independent validation especially important. Explore the dutasteride studies and coverage explanation.^[9]

Gene2Rx evaluates each proposed gene-drug interpretation separately. The SULT1A1 finding concerns topical minoxidil; it does not rank finasteride or dutasteride as better alternatives.

What appears in your Gene2Rx Full Report

The v4 Full Report includes topical minoxidil information for both array and WGS (whole-genome sequencing) uploads. It assesses whether your result contains zero, one, or two copies of the rs1042028 T allele associated with reduced SULT1A1 function.

For array data, processing can use imputation to infer a result from nearby genetic markers when the variant is not directly measured. If your upload cannot support a confident result, the assessment remains indeterminate. An unavailable result is not evidence of normal enzyme function.

The report supplies a specific genetic finding and an explanation of its relevance to topical treatment. It does not measure enzyme activity in your hair follicles, predict oral minoxidil response, or provide finasteride or dutasteride results. See the genotype interpretations or explore the Full Report.

Using genetics in a treatment conversation

These pages focus on medicines used or studied for androgenetic alopecia, also called pattern hair loss. A pharmacogenetic result does not diagnose the cause of hair loss or determine whether you will develop it. Its purpose is to add information about a medicine after the treatment context is understood.

Discuss the finding alongside your diagnosis, treatment duration, consistency of use, side effects, and observed changes in hair growth. For someone carrying the decreased-function SULT1A1 variant, it can offer a plausible contributing explanation for a less-than-expected topical minoxidil response. It cannot establish the cause on its own.

Treatment choice also depends on medical history, other medicines, and personal priorities. Genotype alone should not determine starting or stopping a medicine, changing its dose, or switching formulations.

Sources and further reading

The minoxidil, finasteride, and dutasteride articles review the individual studies in more detail. You can also explore the SULT1A1 gene page.

1. Raftogianis et al. Phenol sulfotransferase pharmacogenetics in humans: association of common SULT1A1 alleles with TS PST phenotype (1997). pubmed.ncbi.nlm.nih.gov
2. Li et al. Characterization of human liver SULT1A1 allozymes with triiodothyronine as the substrate (2001). pubmed.ncbi.nlm.nih.gov
3. Goren et al. Novel enzymatic assay predicts minoxidil response in the treatment of androgenetic alopecia (2014). pubmed.ncbi.nlm.nih.gov
4. Primary source. DailyMed: finasteride 1 mg prescribing information. dailymed.nlm.nih.gov
5. Primary source. DailyMed: Avodart prescribing information. dailymed.nlm.nih.gov
6. Gaboardi et al. 26-SNP Panel Aids Guiding Androgenetic Alopecia Therapy and Provides Insight into Mechanisms of Action (2025). mdpi.com
7. Makridakis and Reichardt. Pharmacogenetic analysis of human steroid 5-alpha-reductase type II: comparison of finasteride and dutasteride (2005). pubmed.ncbi.nlm.nih.gov
8. Ghassemi et al. Androgen receptor repeat polymorphisms and finasteride response (2019). pmc.ncbi.nlm.nih.gov
9. Rhie et al. Genetic variations associated with response to dutasteride in the treatment of male subjects with androgenetic alopecia (2019). journals.plos.org