Minoxidil, finasteride, steroid injections: mechanisms and sensitive scalp safety

Important: This guide is for education only and is not medical advice. Always speak with your own clinician about diagnosis, risks, and treatment choices.

Which treatment best balances mechanism, results, and side effects for sensitive scalps?

If you have a sensitive scalp, past reactions to products, or a history of skin conditions, this guide breaks down the safety profiles of three common hair loss treatments in calm, plain English. I will walk you through what to expect, how to lower risk, and when to call your dermatologist.

At a glance: safety comparison table

Treatment	How it is used	Common side effects	Less common or serious risks	Who should be cautious	Monitoring tips
Low-dose oral minoxidil	Daily pill used off label for hair loss	Increased body hair growth, mild ankle swelling, lightheadedness, faster heart rate¹²³⁴	Rare fluid retention, pericardial issues at high antihypertensive doses; interactions with multiple blood pressure drugs³	People with uncontrolled heart disease, on several antihypertensives, or with history of swelling³	Check blood pressure and heart rate at baseline and during dose changes; report dizziness or swelling²³
Finasteride 1 mg	Daily pill for male pattern hair loss	Decreased libido, erectile or ejaculation changes in a small percentage of users⁵	Mood changes, depression, and suicidal thoughts recently recognized in EU labeling; lowers PSA test values⁶⁷	Men with depression risk, those being monitored with PSA tests⁶⁷	Screen mood before and after starting; adjust PSA values when interpreting labs⁷
Intralesional corticosteroid injections	Triamcinolone injected into patches every 4 to 6 weeks for alopecia areata	Local pain, temporary skin thinning, small visible blood vessels, light or dark patches at injection sites⁸⁹	Rare eyelid pressure or cataract risk near brows; very rare allergy⁸	Patients prone to skin atrophy or with darker skin tones who are concerned about pigment change	Use the lowest effective concentration and correct depth; avoid reinjecting thinned areas⁹

¹²³⁴⁵⁶⁷⁸⁹ map to the Claims Registry at the end.

What is oral minoxidil and how safe is it?

Oral minoxidil is a blood vessel relaxer first approved for severe high blood pressure. For hair, dermatologists prescribe it in much lower doses to help follicles spend more time in the growth phase. This low dose approach is called LDOM, meaning low dose oral minoxidil. Mechanistically, minoxidil opens potassium channels in blood vessel smooth muscle, which lowers resistance and can lower blood pressure².

Most patients tolerate LDOM well when started low and increased slowly. A 2024 analysis found no significant change in average blood pressure with LDOM, although a minority reported mild hypotensive symptoms like lightheadedness². A large clinical experience report showed hypertrichosis, which means extra hair growth on the face or body, in about 15 percent, with systemic side effects such as lightheadedness and ankle swelling below 6 percent³. A 2023 multicenter study in patients with hypertension or arrhythmia reported similar safety to the general population, and highlighted greater risk when LDOM was combined with three or more antihypertensives or with doxazosin³.

Practical steps to lower risk

• Start low. Many dermatologists begin at 0.625 to 1.25 mg nightly and adjust based on response and side effects.

• Track vitals. Check sitting and standing blood pressure and heart rate before starting, after dose changes, and if you feel dizzy²³.

• Flag swelling. Report new ankle or eyelid swelling, shortness of breath, or rapid heart rate promptly³.

• Sensitive scalp tip. Oral therapy avoids scalp contact, so it can be useful if topical products sting or cause flares. On wash days, use a fragrance free cleanser like The Better Scalp Company Sensitive Scalp Shampoo, and apply Sensitive Scalp Conditioner only from mid lengths to ends to keep the barrier calm.

When to avoid or pause
Skip LDOM if you have poorly controlled heart disease, untreated fluid retention, or if you are pregnant or breastfeeding. Coordinate with your cardiologist if you already take multiple blood pressure medicines³.

Citations in this section: 2, 3, 4.

What is finasteride and how safe is it?

Finasteride blocks type II 5 alpha reductase, which lowers dihydrotestosterone in hair follicles. It has been FDA approved at 1 mg for male pattern hair loss since 1997 and is commonly used as a daily tablet⁸.

Sexual side effects appear in a small percentage in clinical trials. Long term randomized studies report drug related sexual adverse effects in fewer than 2 percent of men, and many events resolve with continued use or after stopping⁵. Individual susceptibility varies, and open discussion of risks is important.

Mood risks now appear in official labeling in parts of the world. In May 2025, the European Medicines Agency confirmed suicidal thoughts as a recognized side effect of finasteride, particularly the 1 mg dose for hair loss, and introduced a patient card to support early recognition⁶. If you have a history of depression or anxiety, talk with your clinician before starting and monitor mood closely once on therapy.

Finasteride lowers PSA blood test values. PSA is a prostate cancer screening marker. Finasteride can reduce PSA by roughly 50 percent within a year. Clinicians adjust by doubling the measured PSA to estimate the true value, and any rise from your personal PSA low point should be evaluated⁷.

Practical steps to lower risk

• Mood screening. Ask yourself weekly if there is any new persistent sadness, anxiety, panic, or thoughts of self harm. If yes, stop the medication and contact your doctor the same day⁶.

• Sexual health dialogue. If you notice sexual changes, discuss dose adjustment or drug holidays. Many patients improve with time⁵.

• Lab coordination. Tell your primary care clinician or urologist that you take finasteride so PSA interpretation is adjusted correctly⁷.

• Sensitive scalp tip. If topical minoxidil irritates your scalp, finasteride offers a non contact option. Keep your routine gentle with The Better Scalp Company Sensitive Scalp Shampoo and apply Sensitive Scalp Conditioner only from mid lengths to ends to minimize barrier stress.

Citations in this section: 5, 6, 7, 8.

What are corticosteroid injections and how safe are they?

Intralesional corticosteroid injections treat autoimmune patchy hair loss called alopecia areata. The clinician injects a small amount of triamcinolone into affected patches every 4 to 6 weeks. This calms immune attack on follicles and can trigger regrowth in many patients⁸.

Local skin changes are the main risks. The most common side effect is temporary skin thinning at the injection site. Other local effects include small visible vessels and light or dark pigment shifts. These usually improve over time and can be minimized with correct technique⁸. Using the lowest effective concentration and avoiding superficial placement reduce the chance of atrophy or color change⁹.

Special areas require extra caution. Near the eyebrows there is a small risk of increased eye pressure or cataract if steroid diffuses toward the eye, so dosing is lower and spacing is careful⁸.

Practical steps to lower risk

• Ask about concentration. For the scalp, many clinicians prefer 5 mg per mL to balance efficacy and atrophy risk⁸⁹.

• Avoid reinjecting thinned zones. Give atrophic areas time to recover⁸.

• Prep the skin gently. Before your visit, cleanse with The Better Scalp Company Sensitive Scalp Shampoo and avoid exfoliants or retinoids on treatment day. If you condition, apply Sensitive Scalp Conditioner only from mid lengths to ends.

Citations in this section: 8, 9.

Which option is most sensitive scalp friendly?

For stinging or contact dermatitis from topicals, oral pathways reduce local irritation. Oral minoxidil and finasteride do not touch the scalp, which can help if you react to propylene glycol or fragrance. Oral minoxidil may still cause systemic symptoms like lightheadedness or swelling in a small subset²³. Finasteride avoids contact irritation but requires mood and sexual health monitoring⁵⁶.

For patchy alopecia areata, injections target the problem locally. Intralesional steroids are first line for limited patches and allow you to avoid daily pills, but they can leave transient dents or color change in the skin⁸⁹.

Your plan can combine therapies. Some patients use injections to regrow patches and later add topical or oral minoxidil to help maintain results, guided by their dermatologist and tailored to scalp sensitivity¹⁰.

Citations in this section: 10.

How to start safely, step by step

1. Clarify the diagnosis. Pattern hair loss, shedding from stress or illness, and alopecia areata look different and are treated differently. Bring a photo timeline and a list of medications and supplements.

2. Share your sensitivity history. Tell your clinician about fragrance reactions, prior dermatitis, eczema, or psoriasis flares. This steers you toward oral options or injections if needed.

3. Pick a starting lane.

   • Consider LDOM if you cannot tolerate topicals and you do not have uncontrolled heart or kidney disease.

   • Consider finasteride if you are an adult male with pattern hair loss and low depression risk.

   • Consider intralesional steroids if you have patchy alopecia areata confined to small areas.

4. Set monitoring checkpoints.

   • LDOM: baseline and follow up blood pressure and heart rate. Watch for swelling or dizziness²³.

   • Finasteride: mood check weekly for the first 2 to 3 months. Sexual function check in. PSA adjustment plan with your doctor⁵⁶⁷.

   • Injections: photograph the area, watch for dents or color change, and lengthen intervals if skin looks thinned⁸⁹.

5. Care for the scalp barrier. Wash with The Better Scalp Company Sensitive Scalp Shampoo. Apply Sensitive Scalp Conditioner only from mid lengths to ends. Keep water lukewarm, limit harsh scrubs, and avoid fragrance or alcohol heavy styling products.

Frequently asked safety questions

Will oral minoxidil drop my blood pressure?

Most low dose regimens show no significant average blood pressure change, though a minority report lightheadedness or faster heart rate. Start low, check vitals, and report symptoms promptly²³⁴.

Does finasteride always cause sexual side effects?

No. Randomized data show fewer than 2 percent of users report drug related sexual side effects, and many resolve with time or after discontinuation. Individual experiences vary⁵.

What did regulators say about finasteride and mood?

In May 2025, the European Medicines Agency added suicidal thoughts as a recognized side effect for the 1 mg dose used for hair loss and introduced a patient card to support warnings⁶. Discuss screening and monitoring before starting.

Can steroid injections dent the skin permanently?

Most injection related thinning improves over months. Using the correct depth, spacing, and the lowest effective concentration reduces risk. Avoid reinjecting thinned areas until they recover⁸⁹.

Encouragement for next steps

You deserve effective treatment that respects your sensitive scalp. Partner with a board certified dermatologist, start with the safest reasonable option for your health history, and keep the scalp barrier calm between visits. Early intervention prevents frustration and gives you more choices.

Glossary

• Low dose oral minoxidil (LDOM): Small daily dose of minoxidil taken by mouth to support hair growth. Originally a blood pressure drug².

• Hypertrichosis: Extra body or facial hair growth that can occur with minoxidil³.

• Alopecia areata: Autoimmune patchy hair loss treated with local steroids and other immunomodulators¹⁰.

• Intralesional corticosteroid injection: A tiny steroid dose placed into the skin of a bald patch to reduce inflammation⁸.

• PSA (prostate specific antigen): A blood test used in prostate cancer screening. Reduced by finasteride⁷.

• 5 alpha reductase inhibitor: A drug class that lowers dihydrotestosterone. Finasteride is an example⁸.

• Atrophy: Thinning or denting of the skin that can occur after steroid injections but often improves with time⁸.

• Patch test: A small area trial of a product or technique to check for irritation before wider use.

• Eyelid edema: Puffiness around the eyes, a possible minoxidil side effect at higher sensitivity³.

• Telangiectasia: Small visible blood vessels that can appear after steroid injections⁸.

Claims Registry

Citation #	Claim(s) supported	Source title + authors + year + venue	Accessed date (America/New_York)	Anchor extract	Notes
1	Hypertrichosis occurred in about 15 percent and systemic effects under 6 percent in a large series	Oral Minoxidil Offers Strong Results Against Alopecia. Bergfeld et al., 2022, Cleveland Clinic ConsultQD	2025 11 21	“Hypertrichosis… 15.1%. Systemic adverse effects… 5.5%.”	Clinician review summarizing 1,404 patient series.
2	LDOM shows no significant average blood pressure change and mild hypotensive symptoms are possible	Low dose oral minoxidil does not significantly affect blood pressure. Chen et al., 2024, JAAD	2025 11 21	“LDOM appears to be a safe treatment… no significant impact on blood pressure.”	Peer reviewed meta analysis.
3	LDOM safety in patients with hypertension or arrhythmia and caution with multiple antihypertensives	Safety of Low Dose Oral Minoxidil in Patients With Hypertension or Arrhythmia. 2023, Actas Dermo Sifiliográficas	2025 11 21	“Favorable safety profile… Most common systemic AE were lightheadedness and fluid retention… combination with 3 or more antihypertensives… higher risk.”	Multicenter retrospective study.
4	Minoxidil mechanism as potassium channel opener and antihypertensive	Minoxidil. Patel et al., 2023, StatPearls (NCBI Bookshelf)	2025 11 21	“Minoxidil exerts its antihypertensive effect by opening… potassium channels.”	Standard pharmacology reference.
5	Finasteride sexual side effects occur in fewer than 2 percent in long term trials	Finasteride and sexual side effects. Mysore, 2012, Indian J Dermatol Venereol Leprol (PMC)	2025 11 21	“Sexual side effects… occurred in <2% of men.”	Review of randomized data and long term follow up.
6	EMA confirmed suicidal thoughts as a side effect for 1 mg finasteride and added a patient card	EU drugs regulator confirms suicidal thoughts as side effect of hair loss drug. Reuters, 2025	2025 11 21	“EMA has confirmed that suicidal thoughts are a side effect… particularly in its 1 mg form… patient card.”	Major wire service reporting regulatory action.
7	Finasteride lowers PSA and requires adjusted interpretation	PROPECIA (finasteride) label. FDA, 2012	2025 11 21	“PSA decreased… PSA levels are decreased by approximately 50%.”	Official U.S. label language.
8	Intralesional steroids common adverse effects and technique to reduce atrophy	Intralesional Steroids for Alopecia Areata. Kumaresan, 2010, Indian J Dermatol (PMC)	2025 11 21	“Common adverse effects… pain, atrophy… telangiectasia, hypo or depigmentation… main side effect is minimal transient atrophy.”	Practical review of ILC safety and technique.
9	Lowest effective triamcinolone concentration minimizes atrophy and telangiectasia	Benefit of different concentrations of intralesional triamcinolone acetonide. Chu et al., 2015, JAAD	2025 11 21	“Using the lowest effective concentration minimizes local side effects of skin atrophy and telangiectasia.”	Specialty journal guidance.
10	AAD outlines typical alopecia areata care pathway including corticosteroids and minoxidil	Alopecia areata diagnosis and treatment. American Academy of Dermatology, 2024	2025 11 21	“A common treatment plan involves applying a corticosteroid… later minoxidil… to keep the hair that has regrown.”	Public guidance from an authoritative body.