The Stronger Strands System: ProGRO Density+ & Biotin Essentials
Your hair has two separate problems. Most products only solve one. ProGRO Density+ reduces shedding at the scalp. Biotin Essentials strengthens the strands you're keeping. Clinically-studied, drug-free, with results starting in as little as 6 weeks. So you can stop measuring and just live your life.
ProGRO Density+ · Third-Party Clinical Study
saw an overall improvement
experienced less shedding
noticed new growth*
said their hair looked fuller
saw less breakage
*Perception stat. Based on a 44-day third-party clinical study, 30 participants, Apr. 2026.
Real Results
Kitty noticed visible improvement in her part width starting around week 6.
"It absorbs quickly and doesn't interfere with my hairstyle or make my curls look oily. My scalp felt calm and balanced throughout the time I was using it."
Kitty Y. (@kittyluvkitkat) · Verified Buyer · Individual results may vary.
Inside ProGRO Density+
Visible hair thinning has more than one cause. VitaGRO Complex is formulated to address multiple triggers at once, not just one pathway.
Free from
"I've been using the ProGRO Density+ Scalp Serum for a little while and I'm already seeing a difference in how my hair looks and feels."
Yarelyn C. · Verified Buyer · ProGRO Density+
Inside Biotin Haircare Essentials
Shampoo, conditioner, and Oh My Growth booster, working together to strengthen strands and build visible volume with every wash.
said they'd switch from their current shampoo and conditioner
noticed increased thickness
Based on a 28-day third-party clinical study using full biotin system, 33 participants, Aug. 2025.
Most people who don't see results quit too soon. Here's what's actually happening.
You might not notice it right away. But something is shifting. The drain is a little quieter. Biotin starts making your hair feel healthier and more vibrant through the lengths. Stay consistent. This is what the next stage depends on.
The shedding has started to ease. You're standing at the mirror longer. Hair feels thicker, less like it'll break if you look at it wrong. This is around week 6, when the clinical results start to show.
Visibly fuller-looking hair. A scalp that doesn't feel tired. You haven't measured your part in a while. Not because you forgot, but because you stopped worrying about it.
Timing varies from person to person. Journey is for illustrative purposes only. Consistent daily use is essential for the best results.
ProGRO Density+ takes a multi-pathway approach: no prescriptions, no hormonal risk, no waiting four months to see if it's working.
| ProGRO Density+ | Minoxidil / Finasteride | Serums Without Clinical Data | |
|---|---|---|---|
| Science | ✓ Clean multi-pathway formula | Single-path; uses harsh drugs | Surface-level care |
| How it feels | ✓ Residue-free, lightweight, non-irritating | Irritation + early shedding common | Gentle but often leaves residue |
| Time to results | ✓ 6–12 weeks | 4–6 months | 16+ weeks |
| Safety | ✓ Drug-free; suitable for women & men | Prescription or hormone risk | Usually clean |
| Color/style safe | ✓ Yes. Dries clear, style as usual | Often not | Sometimes |
| Gives back | ✓ Every bottle gives back | — | Minimal |
Comparison reflects ProGRO Density+ vs. common alternatives. Individual results vary.
Consistency is what drives results. Clinical results started showing at 6 weeks. The sooner you start, the sooner your strands do too.
"Love this product! Just a nickel-size dollop leaves my hair shiny and so healthy looking, plus there’s less hair in the sink when I comb it out."
Linda · Verified Buyer · Biotin Haircare Essentials
"I've been using the SoapBox ProGRO Density+ Hair & Scalp Serum for a little while and I'm already seeing a difference in how my hair looks and feels."
Yarelyn C. · Verified Buyer · ProGRO Density+
"As someone with PCOS, I do experience hair fall and have fine hair on my scalp. This has made a real difference in how full my hair looks."
Khushmeet A. · Verified Buyer · ProGRO Density+
Starting at $1.67/day on subscribe. Choose your supply below, or start with one product at a time.
ProGRO Density+ + Biotin Haircare Essentials: shampoo, conditioner, and Oh My Growth booster. The complete routine for both scalp and strands.
Choose your supply
The scalp serum on its own. Clinically-studied VitaGRO Complex for visibly fuller-looking, stronger-feeling hair.
Choose your supply
The strengthening routine on its own. Shampoo, conditioner, and Oh My Growth booster for stronger, fuller-looking strands.
Choose your supply
"My hair looks fuller and feels stronger after each use. Highly recommend!"
Leticia CK · Verified Buyer · Biotin Haircare Essentials
Ships in 1–2 business days · Free shipping on $50+
Check with your doctor before use if you are pregnant or breastfeeding, have an active scalp condition, are managing an autoimmune condition affecting your hair, or are currently using Minoxidil or Finasteride.
The Stronger Strands System works in two daily steps. One targets the scalp, one supports every strand.
ProGRO Density+ Serum
Part your hair into sections and apply the dropper directly to your scalp. No rinsing needed. Lightweight and fast-absorbing.
Biotin Haircare Essentials
Work the Biotin Shampoo into wet hair, lather, and rinse. Follow with Biotin Conditioner, leave on 2–3 minutes.
After conditioning, apply Oh My Growth Leave-In Rinse from roots to ends. Leave in for 5 minutes, then rinse.
Color-safe and residue-free. Continue with your normal styling routine.
In the ProGRO Density+ clinical study, results were visible in as little as 6 weeks with consistent daily use. Some people notice changes earlier; some later. The most consistent thing across positive experiences is staying with the routine. If you're only evaluating at 3 or 4 weeks, you may be stopping right before the change becomes visible.
Some people notice a temporary increase in shedding in the first few weeks. This is a known early response and typically settles. Most people who stay consistent through 6 weeks see the shedding reduce. If shedding is severe or persists beyond 6 to 8 weeks, consult a dermatologist.
ProGRO Density+ is lightweight and formulated to absorb without residue. Apply directly to the scalp, not the lengths, and let it absorb before styling. If you find it heavy, try a slightly smaller amount or apply on dry hair before bed.
ProGRO Density+ is drug-free, with no Minoxidil or Finasteride. For most people it fits easily into an existing routine. Check with your doctor before use if you are pregnant or breastfeeding, have an active scalp condition, are managing an autoimmune condition affecting your hair, or are currently using Minoxidil or Finasteride.
All Soapbox products come with a 90-Day Satisfaction Promise. If you're not satisfied after trying ProGRO Density+ for up to 90 days, return it. No questions, no strings attached. The promise covers ProGRO Density+, Biotin Haircare Essentials, and the Stronger Strands System.
Minoxidil is an FDA-approved drug that works by extending the hair growth cycle. ProGRO Density+ is a drug-free serum that works differently, targeting scalp environment, follicle support, and visible density through our VitaGRO Complex™. It won't produce the same results as prescription Minoxidil in cases of significant clinical hair loss. What it offers is a clinically tested, drug-free option for people experiencing early or stress-related thinning who want to act without starting a pharmaceutical. If you're already on Minoxidil, check with your doctor before adding a new topical.
Yes. ProGRO Density+ is applied directly to the scalp, not the hair lengths or color, so it won't affect your color treatment. The Biotin Shampoo and Conditioner are also sulfate-free, silicone-free, and color-safe, formulated specifically to work with color-treated hair.
Yes, no commitment required. You can pause, skip, or cancel your subscription at any time from your account, with no fees. The Subscribe & Save pricing saves you $5/month on ProGRO and $3/month on Biotin, for as long as you stay subscribed.
Every Bottle Gives Back
It's as easy as 1 for 1. For every product purchased, we donate a bar of soap and support hygiene education worldwide. Together, we've donated more than 60 million bars and counting. Because what you put on your hair and body should stand for something.
bars donated
nonprofit partners
