What Medications and Supplements Should Not Be Taken with Hair Loss Medication?

There is one common concern among people who are just starting hair loss medication:

“Will it interfere with the medicines I’m taking now?”

If you search online, there is a lot of scary information, but if you carefully look at the actual academic literature and pharmacokinetic data,

most of it is not something you need to worry about excessively.

In particular, finasteride, dutasteride, and oral/topical minoxidil each have different metabolic pathways and characteristics, so if you clearly distinguish the points that truly require caution, you can continue taking them much more safely.

Below, I have organized a practical guide centered on questions that are commonly asked in the clinic.

What Medications and Supplements Should Not Be Taken with Hair Loss Medication?

Summary

Finasteride is a drug for which almost no interactions have been reported¹

Dutasteride has a higher dependence on CYP3A4 metabolism, so caution is needed when used with some potent inhibitors²

Oral minoxidil was originally a blood pressure medication, so careful monitoring is needed for people with cardiovascular disease or those taking blood pressure medication³⁴

Topical minoxidil has almost no systemic absorption, so it generally does not cause problems with most medications⁵

Among supplements, high-dose biotin requires more caution than saw palmetto (important because it may distort blood test results)⁶

There are almost no absolute contraindicated combinations, and current health status, the list of medications being taken, and liver and cardiovascular function are the key variables

Q1. Is it okay to take finasteride with other medications?

This is a drug for which major conflicts have not been reported with most medications.

Finasteride does undergo metabolism through the CYP3A4 pathway in the liver, but drug data repeatedly confirm that no meaningful changes in concentration or increase in side effects have been found through this process¹.

• Anticoagulants

• Blood pressure medications

• Diabetes medications

• Lipid-lowering medications

No clinically significant interactions have been reported even with major chronic disease medication groups¹. The patient’s liver function, duration of medication use, and whether they are taking multiple medications are more important than the drug combination itself.

Q2. Why does dutasteride require more caution?

Because its dependence on CYP3A4 metabolism is higher than that of finasteride².

Dutasteride is in the same class of medication, but when processed in the liver, it is more affected by a specific enzyme (CYP3A4).

So, if you have been taking the following medications for a long time, there is a possibility that the concentration may increase.

• Some antiviral drugs

• Potent antifungal drugs

• Certain cardiovascular drugs

This combination is not prohibited, but if liver function is weak or if multiple medications are being taken long term,

it is generally advisable to design the dosage and follow-up more carefully².

Q3. Why should oral minoxidil be used cautiously with blood pressure or heart medications?

Because it was originally a vasodilating treatment for hypertension³.

Low-dose minoxidil is commonly used these days, but its original action is vasodilation, so the following may occur:

• Blood pressure dropping too much

• Tachycardia

• Edema

• Palpitations

In particular, closer and more precise combination planning is needed for the following people⁴.

• History of cardiovascular disease

• Taking multiple types of blood pressure medications

• History of renal failure or heart failure

• Older adults

Q4. Does topical minoxidil have these risks too?

Topical formulations have almost no systemic absorption, so most people do not need to worry⁵.

Studies have repeatedly confirmed that no meaningful changes in blood pressure, pulse, or weight were observed⁵. However, people with heart disease should avoid actions outside the normal range, such as applying excessive amounts.

Q5. Can supplements like saw palmetto be taken together with hair loss medication?

Because some of their mechanisms of action overlap, long-term combined use may increase side effects.

Saw palmetto, beta-sitosterol, and pumpkin seed extract have 5α-reductase-inhibiting mechanisms, so they are similar to finasteride and dutasteride and may be more likely to cause sexual side effects.

They may also lower PSA (prostate-specific antigen) levels, which could create confusion when interpreting screening results.

They are not impossible to use together, but simplifying the supplement regimen so that overlapping mechanisms do not stack is a clinically safer approach.

Q6. Why should high-dose biotin be used with caution?

It is not because it interacts with hair loss medication, but because it can distort blood test results⁶.

Biotin is included in many hair supplements, but official agencies have warned that it can produce false results in the following tests⁶.

• Troponin tests used to assess myocardial infarction

• Thyroid function tests

• Some hormone tests

Because severely incorrect results can interfere with important medical decisions, some organizations recommend stopping biotin at least 48 to 72 hours before testing.

What Medications and Supplements Should Not Be Taken with Hair Loss Medication?

Summary Table

Category	Level of Caution	Reason	Key Point
Finasteride	Low	Undergoes CYP3A4 pathway but almost no clinical interactions¹	Broad range of use with most medications
Dutasteride	Moderate	Greater effect from CYP3A4²	Monitoring needed for long-term users of potent inhibitors
Oral minoxidil	High	Vasodilation may affect cardiovascular system and blood pressure³⁴	Combination planning needed for high-risk patients and those on multiple medications
Topical minoxidil	Very low	Minimal systemic absorption⁵	Only avoid excessive application
Natural ingredients such as saw palmetto	Moderate	Possible overlap in mechanism of action	Possible increase in side effects and confusion in PSA interpretation
High-dose biotin	Moderate to high	May distort blood test results⁶	Test scheduling must be managed

There are not many combinations that absolutely should not be taken with hair loss medication.

What matters more is each person’s health status, liver function, cardiovascular status, and the types of medications they are currently taking.

• Finasteride is stable

• Dutasteride requires caution with certain medications

• Oral minoxidil depends mainly on whether cardiovascular disease is present

• Topical minoxidil is rarely a problem

• Supplements require special caution with high-dose biotin

If you clearly understand these criteria, you can make a much safer and more realistic hair loss treatment plan.

It is now time for hair to grow, this was Kim Jin-oh.

Pilsaengsinmo (必生新毛).

Written by: Kim Jin-oh of New Hair Plastic Surgery Clinic (Public Relations Director, Korean Society of Plastic and Reconstructive Surgeons / Academic Director, Korean Society for Laser Dermatology and Hair)

References

1. MedCentral (2024). Finasteride – Drug Monograph (Oral). MedCentral. Available at: https://www.medcentral.com/drugs/monograph/1548-398016/finasteride-oral

cited: “Finasteride does not affect the cytochrome P-450 (CYP) enzyme system. No clinically meaningful drug interactions have been identified.”

2. AG-Dutasteride (2025). Product Monograph. Health Canada Drug Product Database. Available at: https://pdf.hres.ca/dpd_pm/00078735.PDF

cited: “Because of the potential for drug-drug interactions, use caution when prescribing dutasteride to patients taking potent, chronic CYP3A4 enzyme inhibitors (e.g., ritonavir).”

3. MedCentral (2024). Minoxidil (Oral) – Drug Monograph. MedCentral. Available at: https://www.medcentral.com/drugs/monograph/8680-382608/minoxidil-oral

cited: “Direct vasodilators, including minoxidil, may be used in combination with other antihypertensive therapies (e.g., a diuretic and a β-adrenergic blocking agent).”

4. Ke, B. et al. (2024). A Retrospective Study on the Safety of Systemic Minoxidil. Hair Transplant Forum International, 34(6), 206–212.

cited: “In particular, caution should be taken when combining systemic minoxidil with cardiovascular medications in vulnerable populations.”

5. Fiedler-Weiss, V.C. (1987). Topical minoxidil solution (1% and 5%) in the treatment of androgenetic alopecia. Journal of the American Academy of Dermatology, 16(3), 718–726.

cited: “Systemic absorption of topically applied and occluded minoxidil solutions (1% and 5%) was minimal; no clinically significant changes in blood pressure, weight, or pulse rate were detected.”

6. Health Canada (2025). Biotin and the risk of false lab test results. Government of Canada. Available at: https://www.canada.ca/en/health-canada/services/drugs-health-products/medical-devices/biotin-risk-false-lab-test-results.html

cited: “High biotin levels can interfere with many lab tests that use biotin technology, including troponin tests and thyroid function hormone tests.”

[This post is written directly by a plastic surgery specialist for the purpose of providing information in accordance with Article 56, Paragraph 1 of the Medical Service Act. Hair transplant surgery and treatment may have side effects, and you should make a careful decision through consultation with a specialist.]