You may have noticed that a vast majority of Metabolic Maintenance products are contained in amber glass bottles as opposed to the plastic containers more commonly used by our colleagues and competitors in the nutritional supplement industry. Although we agree that amber glass is beautiful, this choice is not purely cosmetic. Here we will explain to you just a few of the reasons Metabolic Maintenance is proud to make the choice of glass over plastic whenever possible, even when it means sacrificing some convenience and cost on our end.

Are glass bottles better for your health?

Plastic bottles can be made from a variety of different chemicals, some of which are known endocrine disruptors such as bisphenol-A (BPA) and phthalates. We also know that ordinary storage factors like heat and time can cause leaching of these chemicals into the stored product. This means that when you consume whatever is stored inside the bottle, you consume a little bit of the bottle along with it. Some of these chemicals haven’t been around long enough, or haven’t been tested thoroughly enough for us to know the long-term consequences of ingestion, but for some of these chemicals, we know that ingestion is related to negative effects on the brain, interference with hormones and the health of our reproductive systems, and can even have carcinogenic properties, contributing to cancer development [1-4]. 

On the other hand, glass is nonporous and impermeable, meaning it does not chemically interact with, or leach into the products kept inside [5]. This is not only important for the maintenance of taste and aroma of the stored products, but also protects their integrity and strength during storage, and protects your body from ingesting anything that isn’t part of the supposed formula.

Why amber glass?

There are some supplement ingredients and nutrients that are light-sensitive, meaning that they are more likely to change or degrade when exposed to UV rays. While opaque plastic containers can protect supplements from the light, the potential drawbacks to ingesting products stored in plastic make this a less attractive option. Although glass is transparent, adding color can help protect contents from UV rays. While green tint adds some protection and cobalt blue is more protective, it is amber glass that adds the highest level of UV protection to your container while still allowing you to see what’s left inside [6].

Is glass better for the environment?

This is probably the most important argument for choosing glass over plastic. While both glass and some plastics are technically “recyclable”, glass bottles can be recycled back into new glass bottles endlessly without degrading or losing integrity, while plastics cannot. Plastic can really only be “downcycled” from bottles and containers into a few materials like carpet padding or plastic lumber. Once these products are discarded, they cannot be recycled again. On top of that, the US used to send the bulk of our plastic recyclables to China for processing, but China has stopped taking most US shipments of waste like this, so much more plastic is ending up in US landfills, without much hope of being recycled in the future. 

It has been estimated that only about 9% of plastic ends up getting recycled, and again, it’s not true recycling, but downcycling, and every plastic container, package, or bottle we buy is always brand new [5]. Glass recycling rates in the US are a little better, at approximately 33%, and there is potential for more positive change. Other countries, such as Switzerland and Germany, have glass recycling rates as high as 90% because glass is a truly recyclable material [5]. 

One problem with the constant manufacturing of new plastics is the environmental destruction that accompanies drilling for the petroleum needed to make new plastic products. Drilling for oil can result in oil spills, which famously contaminates surrounding soils and water, can cause horrendous fires and explosions, and leaves irreparable damage in its wake to the ecosystems drilled through, let alone the health of the people that inhabit those areas. 

Then there is the carbon footprint of manufacturing plastic. Not only do plastic products themselves emit CO2, (the emissions from plastic in 2015 were equivalent to nearly 1.8 billion metric tons of CO2), but the factories that are used to create plastic are also likely to run on fossil fuels and produce emissions [5]. 

While we first worry about toxic chemicals from plastic containers leaching into our food, drinks, and supplements, a greater, later concern is the fact that plastic products (very slowly) degrade in landfills or wherever they land. As they degrade, those same toxic chemicals are leached into the environment as microplastics, which pollute our waterways, soil, and the air we breathe [5]. Even if glass doesn’t make it into recycling for new glass, it will never leach toxic chemicals into the soil, water, or air.

As a non-degrading material, glass containers are often better for repurposing around the house too, before you recycle them. Even small vitamin bottles can be repurposed when empty. Try using them as travel-sized containers for beauty products in your carry on luggage, or as a bud vase in the window sill for a vintage look.

Are there better options than plastic and glass?

As modern culture becomes more environmentally and health-conscious, great strides are being made in packaging materials that respect these changing values. At Metabolic Maintenance, we are doing our best to stay abreast of possible packaging options for the future, while continuing to fulfill the needs of our customers with the consistency they trust. We currently package as many products as possible in glass, and when you open a shipment from us, you will notice they have been padded with biodegradable packaging materials, never styrofoam. We will continue to do our best to support you, your health, and the health of our Earth as our company grows and evolves with our changing culture.


  1. Bienkowski 2014. Bienkowski, Brian. 2014. “BPA Triggers Changes in Rats That May Lead to Breast Cancer.” Environmental Health News, July 2.
  2. Bienkowski and Environmental Health News 2014. Bienkowski, Brian and Environmental Health News. 2014. “BPA Exposure Linked to Prostate Cancer.” Scientific American, January 7.
  3. CA EPA 2010. California Environmental Protection Agency. 2010. Chemicals Known to the State to Cause Cancer or Reproductive Toxicity. April 2, 2010. Sacramento, CA: State of California Environmental Protection Agency, Office of Environmental Health Hazard Assessment.
  4. Mattsson, Karin, et al. “Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain.” Scientific Reports 7.1 (2017): 1-7.
  5. Kellogg, Kathryn. “Which is Better For The Environment? Glass or Plastic?” Going Zero Waste. September 12, 2019.
  6. Levins, Cory. “The Science Behind Amber Glass: How These Bottles Protect Liquids.” Air Sea Containers. January 26, 2019.