Harley Street HT Clinics
Valued member
When deciding on a hair loss treatment regime, often, the most common dilemma patients’ face is choosing between oral and topical finasteride. While both target the exact same root cause of male pattern hair loss, androgenic alopecia, however, they differ fundamentally in how they enter your system, how they circulate in your blood, and their potential side effect profiles.
Topical finasteride 0.1% provides direct suppression of dihydrotestosterone (DHT) at the scalp level, with low systemic absorption. While finasteride 1mg taken orally works systemically to decrease DHT levels across the entire body.
From Prostate to Prevention
1mg Finasteride is often considered the standard for stabilising male pattern baldness. Although it started as a treatment for enlarged prostate in 5mg format, and hair growth was found as side effect. They discovered that a lower dose, 1mg was enough to suppress scalp dihydrotestosterone (DHT) by 60% to 70% while keeping side effects to a minimum. This led to FDA approval in 1997, producing the 1mg pill used by millions today.
Oral vs. Topical: The Technical Breakdown
How is it Taken?
Oral Finasteride (1mg Pill) – Ingested into the digestive system, taken daily creating a body wide absorption of reducing DHT.
Topical Finasteride (Spray, Gel, or Liquid) - Applied directly to the scalp; targeting the DHT receptors attached to scalp hair follicles.
Systemic Exposure
Oral Finasteride - High presence in the bloodstream (plasma concentration), once in the bloodstream, about 90% binds to plasma proteins and circulates throughout the body. It distributes into tissues such as the prostate, genital skin, semen.
Topical Finasteride – topical finasteride results in minimal systemic exposure, depending heavily on the solution's concentration. If using a standard 0.25% solution (2.275 mg/mL), applying 0.1 mL (100 µL) delivers approximately 0.2275 mg of finasteride to the scalp.
DHT Suppression
Oral Finasteride - Heavily reduces DHT throughout the entire body (serum DHT), cutting blood DHT by 55% to 70% and scalp DHT by roughly 50%.
Topical Finasteride – Topical finasteride reduces scalp dihydrotestosterone (DHT) by roughly 50% to 70% while suppressing systemic serum DHT by only 10% to 35% at standard clinical doses.
Side Effects
Oral Finasteride - Carries well-documented ~2% probability of systemic sexual side effects or infrequent mood changes.
Topical Finasteride – Significantly lowers the risk of systemic issues minimising the likelihood of full-body side effects like mood shifts, low libido, or erectile issues, but can cause local scalp irritation or redness.
Results & Efficacy
Oral Finasteride - Oral finasteride (1 mg daily) successfully halts hair loss progression and stimulates regrowth in approximately 80% to 90% of men with male pattern hair loss.
Topical Finasteride - Topical finasteride delivers hair regrowth and stabilisation comparable to oral finasteride (1 mg daily).
Summary
Regardless, using topical or oral Finasteride the mechanism of action is the same. Both oral and topical finasteride function as 5-alpha-reductase inhibitors. They work by blocking the enzyme that converts regular testosterone into DHT. DHT triggers the androgen receptor on genetically receptive hair follicles and starts the process of reducing the growth phase of the hair cycle and lengthening the dormant stage. As a result, both options can help to stabilise genetic hair loss and improve the quality of hair regrowth. As with oral Finasteride, the topical application must be stopped before trying to conceive. While topical formulas absorb into the bloodstream at lower levels than oral pills, healthcare providers advise pausing all forms of the medication as a precaution. They can still be absorbed into the skin off clothing bed covers, and pillows.
Topical finasteride 0.1% provides direct suppression of dihydrotestosterone (DHT) at the scalp level, with low systemic absorption. While finasteride 1mg taken orally works systemically to decrease DHT levels across the entire body.
From Prostate to Prevention
1mg Finasteride is often considered the standard for stabilising male pattern baldness. Although it started as a treatment for enlarged prostate in 5mg format, and hair growth was found as side effect. They discovered that a lower dose, 1mg was enough to suppress scalp dihydrotestosterone (DHT) by 60% to 70% while keeping side effects to a minimum. This led to FDA approval in 1997, producing the 1mg pill used by millions today.
Oral vs. Topical: The Technical Breakdown
How is it Taken?
Oral Finasteride (1mg Pill) – Ingested into the digestive system, taken daily creating a body wide absorption of reducing DHT.
Topical Finasteride (Spray, Gel, or Liquid) - Applied directly to the scalp; targeting the DHT receptors attached to scalp hair follicles.
Systemic Exposure
Oral Finasteride - High presence in the bloodstream (plasma concentration), once in the bloodstream, about 90% binds to plasma proteins and circulates throughout the body. It distributes into tissues such as the prostate, genital skin, semen.
Topical Finasteride – topical finasteride results in minimal systemic exposure, depending heavily on the solution's concentration. If using a standard 0.25% solution (2.275 mg/mL), applying 0.1 mL (100 µL) delivers approximately 0.2275 mg of finasteride to the scalp.
DHT Suppression
Oral Finasteride - Heavily reduces DHT throughout the entire body (serum DHT), cutting blood DHT by 55% to 70% and scalp DHT by roughly 50%.
Topical Finasteride – Topical finasteride reduces scalp dihydrotestosterone (DHT) by roughly 50% to 70% while suppressing systemic serum DHT by only 10% to 35% at standard clinical doses.
Side Effects
Oral Finasteride - Carries well-documented ~2% probability of systemic sexual side effects or infrequent mood changes.
Topical Finasteride – Significantly lowers the risk of systemic issues minimising the likelihood of full-body side effects like mood shifts, low libido, or erectile issues, but can cause local scalp irritation or redness.
Results & Efficacy
Oral Finasteride - Oral finasteride (1 mg daily) successfully halts hair loss progression and stimulates regrowth in approximately 80% to 90% of men with male pattern hair loss.
Topical Finasteride - Topical finasteride delivers hair regrowth and stabilisation comparable to oral finasteride (1 mg daily).
Summary
Regardless, using topical or oral Finasteride the mechanism of action is the same. Both oral and topical finasteride function as 5-alpha-reductase inhibitors. They work by blocking the enzyme that converts regular testosterone into DHT. DHT triggers the androgen receptor on genetically receptive hair follicles and starts the process of reducing the growth phase of the hair cycle and lengthening the dormant stage. As a result, both options can help to stabilise genetic hair loss and improve the quality of hair regrowth. As with oral Finasteride, the topical application must be stopped before trying to conceive. While topical formulas absorb into the bloodstream at lower levels than oral pills, healthcare providers advise pausing all forms of the medication as a precaution. They can still be absorbed into the skin off clothing bed covers, and pillows.
