What Is a Dildo? A Beginner's Guide to Materials, Shapes, and How to Pick One

The dildo is the oldest sex toy in human history — the earliest archaeological example is a polished phallus carved from siltstone, dated 28,000 years old, found in Hohle Fels, Germany. The mechanics haven't changed; what's changed is the materials science, design space, and the size of the consumer market. This guide covers what to actually know before buying one.

Dildos | Realistic, G-Spot & Strap-On Sex Toys Dildos are the largest single category in any sex-toy catalog because the design space is huge — material (silicone/glass/metal), size, curvature, vibration, suction-cup base. The collection lets you filter what matters. Shop category →

What a dildo is (and isn't)

Definition: a non-vibrating insertable toy. The non-vibrating part is what distinguishes it from a vibrator, though many products blend categories. Three usage modes:

• Vaginal. Most common solo use. Designs vary by length, girth, curve (for G-spot targeting), and texture.
• Anal. Requires a flared base — the rectum has muscles that contract reflexively and can pull objects in. ER retrievals of dildos without flared bases are unfortunately routine. This is the single most important safety rule in the category.
• Strap-on / partnered. Worn in a harness for partner use. Often paired with a base specifically designed to lock into harness rings (O-ring system).

Some dildos are dual-purpose; many are designed for one mode. Read the product description.

Materials: what's body-safe and what isn't

Material matters more than any other spec. The body-safe ones are non-porous (can be properly cleaned), chemically stable (don't degrade), and don't leach plasticizers.

Body-safe

• Medical-grade silicone. The default. Body-safe, non-porous, durable, hypoallergenic. Holds body heat well, slightly grippy. The recommended starting material for most buyers. Lifetime: 5+ years with proper care.
• Borosilicate glass. Pyrex-grade glass. Non-porous, smooth, body-safe, can be temperature-played (warm or cool before use). Hard, smooth, no flex. Often the second toy in a collection.
• Stainless steel. Heavy, smooth, non-porous, dishwasher-safe. Cool to the touch initially, warms with use. Premium feel but expensive.
• ABS plastic. Body-safe hard plastic. Less common in dildos than vibrators. Fine but usually not the most pleasurable feel.

Avoid

• Jelly rubber, PVC, "rubber." Porous, can't be properly cleaned, often contain phthalates. Smell test: if it smells chemical out of the package, it is. Even "phthalate-free" labels on these materials are unreliable.
• TPR/TPE (thermoplastic rubber/elastomer). Marketed as silicone alternative. Porous, breaks down faster, often contains plasticizers. Acceptable as a "trial" toy in the budget tier but not for long-term use.
• "Soft skin" / Cyberskin / UR3. Realistic-feeling but porous; can't be sterilized; degrade within months.

The rule: if you can't tell from the listing what the material is, assume it's the cheap version. Reputable brands name their materials specifically — "100% medical-grade silicone" is the kind of phrasing to look for.

Shape, size, and curve

Length

For first-time buyers, 4–6 inches insertable is the sweet spot. Average vaginal depth is about 4–5 inches at rest, 5–7 inches when aroused — past that, you're pushing against the cervix, which is uncomfortable for most people. Anal use generally tolerates similar lengths.

Girth (diameter)

Beginner: 1.0–1.25 inches in diameter (3.0–3.5 inches circumference). Most starter dildos sit here. Going wider is a progression, not a starting point.

Curve

A slight upward curve targets the G-spot (in vaginal use) or prostate (in anal use). Both are 2–3 inches inside, on the front wall. Curved dildos are usually labeled "G-spot" or "P-spot." For pure penetrative use without targeted stimulation, straight is fine.

Base

• Suction cup: sticks to flat surfaces (tile, glass), enables hands-free use in different positions. The most useful base type for solo use.
• Flared / flat: required for anal use. Prevents loss into the rectum.
• O-ring compatible: for harness/strap-on use.

GLAS 6 Inch Curved G-Spot Glass Dildo A 6-inch curved glass dildo — body-safe, no porous material, smooth, non-vibrating, designed for G-spot or P-spot angle. Around $22, in stock. Good first non-silicone option. View product →

Lube compatibility

• Silicone dildo + silicone lube: avoid. Silicone-on-silicone causes degradation of the toy surface within weeks. Use water-based lube only.
• Silicone dildo + water-based lube: safe. The default combination.
• Glass / metal / ABS + any lube: safe with all lube types.
• Anal use: always use lube, ideally a thicker formula. Anus doesn't self-lubricate.

If unsure, water-based works with everything. See our guide on lube and condom compatibility for more.

How to actually use one (the practical bits)

1. Wash before first use with warm water and mild soap. Silicone and glass can also be boiled (3 minutes) or run through a dishwasher's top rack for full sterilization.
2. Use lube generously. More than you think you need. Reduces friction, prolongs comfort.
3. Start slow. Insertion at 70%+ depth on the first attempt is uncomfortable for most. Build up.
4. Anal use: warm-up matters more. Fingers or a smaller plug first. The anal sphincter resists and needs time to relax.
5. Clean after every use. Mild soap and warm water is enough. Air dry or pat dry; don't store damp.
6. Store separately. Two silicone toys touching can cause surface degradation over time. Cotton bag or individual containers.

Solo vs. partnered use

Solo: most common. Helps with self-knowledge — most women learn what works for them this way before being able to communicate it to a partner.

Partnered: a dildo can be used during partner sex (e.g., one partner penetrates with a hand; or oral + dildo combinations) or as a strap-on for non-penis-having partners. The conversation about introducing one is the part most couples find awkward — see our guide on bringing up sex toys with a partner.

The "I'd be replaced by a toy" anxiety some men report is statistically unfounded — surveys consistently find women using toys report higher partnered-sex satisfaction, not lower. The toy adds; it doesn't subtract.

Common mistakes

• Buying too big. The most common first-purchase mistake. Start at 5 inches × 1.0–1.25 inch. Going up is easy; the wrong toy sits in a drawer.
• Buying jelly because it's cheap. The savings disappear when the toy degrades and has to be replaced; meanwhile you've been exposed to plasticizers.
• Anal without a flared base. Surgery-level mistake. Always check the base.
• Silicone lube with silicone toys. Permanent surface damage. Water-based only.
• Skipping cleaning. Bacterial growth on porous or under-cleaned surfaces causes UTIs and yeast infections. Clean every time.

FAQ: dildos

What's the best material for a first dildo?
Medical-grade silicone. Body-safe, non-porous, durable, comfortable. Glass and stainless steel are also body-safe options if you prefer harder, smoother feel.

How big should my first dildo be?
Most experts recommend 4–6 inches insertable length and 1.0–1.25 inches in diameter. This covers most anatomy comfortably and lets you progress later if you want to.

What's the difference between a dildo and a vibrator?
A dildo is non-vibrating; a vibrator is motorized. Many products blend categories — a "vibrating dildo" is technically a vibrator. Pure dildos focus on penetration, shape, and material feel.

Is jelly material really unsafe?
It's not acutely dangerous, but it's porous (can harbor bacteria), often contains phthalates (linked to endocrine disruption in animal studies), and degrades visibly within months. Avoidable with negligible cost premium for silicone.

Do I need a flared base for anal use?
Yes, always. The rectum can pull objects in past the sphincter. Without a flared base, retrieval may require an emergency room visit. This is the single most important safety rule in the category.

How do I clean a dildo?
Mild soap and warm water after every use. Silicone and glass can be boiled for 3 minutes for full sterilization. Air dry. Store in a clean, dry place — separately from other silicone toys.

Can I use any lube with any dildo?
Water-based lube is universally safe. Silicone lube is safe with glass, metal, and ABS, but degrades silicone toys. Oil-based lube is fine with non-porous toys but breaks down latex condoms.

Bottom line

A dildo is a simple object whose details matter: medical-grade silicone or borosilicate glass, 4–6 inches × 1.0–1.25 inches for first purchase, slight curve if you care about G/P-spot, suction cup or flared base depending on use, water-based lube. Spend $25–50 on a body-safe option once instead of $10 on a jelly toy three times. The rest is preference.