Fabric frequencies have quickly become one of the most talked-about topics in the wellness world, but much of what’s being shared is incomplete, oversimplified, or just flat-out wrong.

Nearly all of it traces back to a single study conducted in 2003 by Heidi Yellen. While the study is fascinating, it leans heavily into religious interpretation and leaves plenty of unanswered questions.

So instead of repeating headlines, here’s what it actually says:

According to the study, the human body operates on a measurable energetic scale:

• 100 — Perfectly healthy body
• 70–90 — Average, functional health
• 50 or below — Chronic illness
• 15 or below — Severe disease / near death

The core idea: anything interacting with the body, like clothing, can either support or strain this state.

Fabric Frequency Breakdown

Lowest Frequencies (0–15)
Synthetic and heavily processed fibers:

• Polyester — 0
• Acrylic — 0
• Spandex / Lycra — 0
• Nylon — 0
• Viscose — 0
• Rayon — 15
• Silk — 10 (controversial in the study)

These fall at or near the frequency of a severely ill body.

Mid-Range Frequencies (40–70)
Processed natural fibers:

• Conventional cotton (bleached & dyed) — 40
• Conventional cotton (unbleached) — 70

Processing, especially bleaching and dyeing, appears to significantly reduce frequency.

Aligned with the Human Body (100)

• Organic, unbleached cotton — 100

This matches the frequency of a healthy human body.

Extremely High Frequencies (5000)

• Linen — 5000
• Wool — 5000

These are described as “high vibrational” fibers with potential restorative qualities.

However:

• Linen and wool are said to cancel each other out when worn together
• Mixing them with lower-frequency materials may reduce their effect

Despite how definitive some of this sounds, there are major gaps:

• No additional studies exist to validate these findings
• Hemp was not tested
• The impact of plant dyes is unknown
• Measurement was done using an Ag-Environ machine (in angstroms, not hertz) which is tradtionally used to measure agricultural products
• The role of blended materials, trims, and thread remains unstudied

There may be truth to the idea that fabrics carry energetic qualities, and we believe there is, but the science definitely isn’t settled.

Which means the real question is:

What do you believe, and what do you need to see to be convinced?

Shop our organic, regenerative, undyed or plant-dyed clothing here.

STUDY LINK
We were unable to find the link to the original 2003 study, but we were able to locate an extensive 2013 article citing the study here.