Injectables and Implants as Contraceptives

Biology · Reproductive Health · NEET

Injectables and implants are hormonal contraceptives for females. They use progestogens alone, or progestogens combined with estrogen, given as injections or placed as implants under the skin. Their mode of action is the same as oral pills (stop ovulation, stop implantation, thicken cervical mucus), but they work for a much longer time. Memory hook: "Same hormone as the pill, but you do NOT take it daily - one shot or one implant lasts long."
Injectables and Implants (Female Hormonal Contraceptives)Hormone UsedProgestogens ALONEORProgestogens + EstrogenGiven UNDER THE SKINMode of Action (like pills)1. Inhibit ovulation2. Inhibit implantation3. Alter cervical mucusEffective period MUCH LONGERUnder the skin (NOT in uterus) = the key NEET point
Injectables and implants deliver progestogens (alone or with estrogen) under the skin. Their action is the same as oral pills - stop ovulation, stop implantation, thicken cervical mucus - but they last much longer.

Your doubts, answered

Are injectables and implants the same as oral pills?

No, but they use the SAME hormones. NCERT says progestogens alone or progestogens with estrogen can be used as injections or implants under the skin. Pills are swallowed daily; injectables and implants are given as a shot or placed under the skin. The hormones are the same type, so the mode of action is the same as pills.

What is the exact mode of action?

NCERT says their mode of action is 'similar to that of pills.' So, like pills, they inhibit ovulation, inhibit implantation, and alter cervical mucus to prevent or slow entry of sperms. For NEET, remember they act like hormonal pills, not like a barrier or a surgical method.

Why do injectables and implants last longer than pills?

NCERT states 'their effective periods are much longer.' Pills must be taken daily for 21 days each cycle. An injection or an implant releases the hormone slowly under the skin over weeks or months, so the woman does not have to take it every day. This longer effective period is a favourite NEET one-liner.

Is the implant put in the uterus like an IUD?

No. This is the most common trap. Implants are placed UNDER THE SKIN, not inside the uterus. IUDs (like Multiload 375, LNG-20) go inside the uterus. Do not confuse a hormone-releasing IUD (inside uterus) with a hormonal implant (under the skin).

Are injectables and implants for males or females?

They are used by FEMALES only. NCERT clearly says 'can also be used by females as injections or implants under the skin.' There is no male injectable or implant in the NCERT contraception list.

In the NEET 2024 match question, why is 'Implants' matched with 'Progestogens'?

Because implants deliver progestogens (alone or with estrogen) under the skin. In the 2024 List II, 'Progestogens' was the item that matched 'Implants.' The IUDs matched their device names (Lippes loop, Multiload 375, LNG-20), leaving progestogens for implants.

⚠️ The NEET trap
Implants are inserted inside the uterus like an IUD.
Implants are placed UNDER THE SKIN and release progestogens. Only IUDs go inside the uterus.
🧠 Implant = under the skin. IUD = inside the uterus. Different place, do not swap them.

Real NEET questions

2024

Match List I with List II: List I: (A) Non-medicated IUD (B) Copper releasing IUD (C) Hormone releasing IUD (D) Implants List II: (i) Multiload 375 (ii) Progestogens (iii) Lippes loop (iv) LNG-20 Choose the correct answer:

A · A-i, B-iii, C-iv, D-ii
B · A-iv, B-i, C-ii, D-iii
C · A-iii, B-i, C-iv, D-ii
D · A-iii, B-i, C-ii, D-iv
Solution: Lippes loop = non-medicated IUD (A-iii); Multiload 375 = copper releasing IUD (B-i); LNG-20 = hormone releasing IUD (C-iv); Implants use progestogens under the skin (D-ii). So the correct match is A-iii, B-i, C-iv, D-ii.

Solved Reproductive Health NEET PYQs

Try the real previous-year questions from this chapter — each with the answer and a full solution.

See all 33 Reproductive Health NEET PYQs ›
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Frequently asked

What hormones are used in contraceptive injectables and implants?

Progestogens alone, or progestogens in combination with estrogen. These are the same hormone types used in oral pills.

Where are contraceptive implants placed?

Under the skin. NCERT clearly states injections or implants are given 'under the skin,' not inside the uterus.

How do injectables and implants prevent pregnancy?

Their mode of action is similar to pills: they inhibit ovulation and implantation and alter cervical mucus to prevent or slow the entry of sperms.

Why are injectables and implants better than daily pills for some women?

Their effective period is much longer, so a woman does not need to take a tablet every day. One injection or implant works for weeks or months.

Are injectables and implants used by males?

No. NCERT lists them as methods used by females only.