The Short Answer: Generally, no. Toppik Hair Building Fibers are resistant to wind, rain, and perspiration. Because they bond to the hair shaft using a strong static charge, they do not run or streak simply from sweating. [cite_start]However, for heavy cardio or drenching sweat, we highly recommend using FiberHold Spray to create a water-resistant seal[cite: 129].
How to "Gym-Proof" Your Hair
While cheap cotton fibers might clump or drip, high-grade Wool Keratin (Toppik) stays put. Here is the 2-step protocol for active users:
- Step 1: Apply fibers to dry hair before the gym (never apply to wet/sweaty hair).
- Step 2: Mist with FiberHold Spray. This acts like a "clear coat" that repels moisture.
Important Note: While sweat-resistant, fibers are not waterproof against submersion. If you wipe your forehead with a white towel during a workout, do so gently. Aggressive rubbing can transfer the fibers.
Common Activity Questions
Will it run in the rain?
Toppik resists light to medium rain remarkably well. However, in a torrential downpour, some movement may occur. [cite_start]Always carry an umbrella if heavy rain is in the forecast, just to be safe[cite: 128].
Can I wear a hat over it?
Yes. The static bond keeps the fibers on your hair, not the hat. For best results, let the FiberHold spray dry completely (about 2 minutes) before putting on a baseball cap or toque.